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The Best Ultrasonic Cleaner for Delicate Clothing

The Best Ultrasonic Cleaner for Delicate Clothing

Dolfi is a small, portable ultrasonic cleaner for delicate clothing. The device aims to replace hand-washing for textiles, and to provide a much needed solution for laundry on travels. It isn’t meant to be a permanent replacement for washing machines.

Dolfi’s name is actually a tribute to Dolphins, since they’re the most advanced users of ultrasonic technology. The crowdfunding campaign for this product has been widely successful, and a portion of that money was reserved for dolphins research and welfare.


Dolphin jumping out of the water



  • Gentle on fabric
  • Small and portable
  • Simple to use
  • Quiet operation
  • Safe to use
  • Saves energy and water


  • Not useful for larger loads

Does Dolfi Really Work?

Short answer: Yes, it does!

Ultrasonic technology has been used for cleaning since the 50s. It became widely available for medical and industrial applications to clean small, intricate objects and to accelerate surface treatment processes.

Dolfi had a working prototype since 2015, and was distributed among beta testers in 2017.

Since then, thousands of devices have been shipped all over the world.

It may look like magic, but the science behind it is actually well-understood.

What Is an Ultrasonic Cleaner?

Ultrasonic cleaning is a cleaning method that uses sound waves that are beyond the human hearing (above 20KHz). The sound waves agitate the water in a process known as “cavitation”.

This process creates millions of tiny bubbles that implode creating a vacuum in the water and the jet stream created frees the dirt from deep in the fabric.  This is what makes ultrasonic cleaning so effective for washing deep into the fabric where hand washing cannot.

It also works as a mechanical disinfectant against bacteria.


Cavitation Process


What Are Some Alternative Uses for Ultrasonic Cleaners?

Besides cleaning fabrics (which is what Dolfi is meant for), ultrasonic cleaners have been used to clean luxury items such as jewelry, glasses, watches, coins, and fountain pens. It’s also been used to clean laboratory, dental, and surgical instruments due to its disinfectant properties and hands-free mechanism.

Ultrasonic cleaners can wash many objects, including musical instruments, phonograph records, electronic equipment, guns, fishing reels, golf clubs and so on.

Basically, anything that has a lot of delicate parts that can be damaged with manual washing, and also has many crevices that are difficult to reach.

Dolfi can wash some of the items here that aren’t clothing, as long as they’re small and lightweight, like for example the glasses or sunglasses.

What Frequency Do Ultrasonic Cleaners Use?

Ultrasonic cleaners use a frequency range above 20KHz, which is inaudible to the human ear.

The higher the frequency used, the smaller the cavitation bubbles created. Small cavitation bubbles are good for gentle cleaning and for getting into smaller crevices.


Deep Cleaning of ultrasonic technology


How to Use Dolfi?

Using Dolfi is really simple. All you need is water, a waterproof container, detergent, and a power outlet.

You need to have a large container and enough water to allow the cloth to float freely, this creates the best condition to remove the contamination. The recommended ratio is 5 liters of water for every one pound of laundry.

The water should be around 30-40 °C. It should be warm, but not too hot. High temperatures can damage delicate fabrics.

The reason the water has to be warm is that ultrasonic waves travel faster in warmer water, not to mention that it makes cleaning easier.

A ceramic or metal container is better than plastic at reflecting the ultrasound waves, but any waterproof container will work. The easiest container to find is the average kitchen or bathroom sink.

For best results, place the Dolfi device at the bottom of the sink with the logo facing upwards. Make sure there’s at least 5 centimeters of water between the device and the clothing, and that the clothing is floating freely above.

The device itself is very quiet, so you won’t know if it’s working from the sound alone. There are 6 blue lights that indicate how long its been working (each light is for 10 minutes of operation). Most stains should be gone within 30-40 minutes, but you can leave them for a whole 1-hour cycle.


The 4 steps to using Dolfi


Is Dolfi Portable?

Yes! Dolfi is a small device that fits into the palm of your hand.

Because it’s specifically designed for traveling, it comes with interchangeable plugs to match the outlets of different countries you may find yourself in.

Does an Ultrasonic Cleaner Need Detergent?

For the most part, yes. A mild detergent is preferred, especially since you’ll most likely be using Dolfi to wash delicate fabrics.

However, any kind of detergent would work, whether liquid or powder. A higher-quality detergent would ensure better results. 

If you’re washing swimwear, you don’t need to add detergent. Ultrasonic cleaning is effective at removing chlorine and sea salt from cloth with water alone.

If you’re washing an object that isn’t clothing, you have to use a detergent that’s appropriate to the object being cleaned and the type of stain you’re trying to remove. Never use flammable solutions.

How Much Laundry Can Dolfi Wash in One Load?

Dolfi can wash up to 1 Kg of clothing in every load and you’ll need at least 10 liters of water to fit that load. The clothing must be floating freely and have a distance of at least 5 centimeters above the device.

Isn’t It Dangerous to Plug the Ultrasonic Cleaner into the Outlet and Put It in the Water?

Not at all. It may seem counter intuitive to plug the device into an outlet, then place it inside the sink, but it’s totally safe!

Dolfi is housed inside a smooth plastic casing that is waterproof, and the wire itself is flexible and waterproof as well.

The main function of the device requires it to be placed inside water, so it has been tested numerous times for safety. It has been developed in accordance with international standards for electrical devices that work underwater.

If you’re still concerned, it helps to know that there’s only 12 Volts going through the cable at any given time, same like in your trimmer or toothbrush.

Is Dolfi a Replacement for Normal Washing Machines?

No. Dolfi is designed for small loads, with a maximum of 1.5 Kg. Even if you’re using the maximum capacity, you still need enough room for the clothing to float freely, so it’s not convenient for larger loads.

Dolfi is more suitable for the kind of objects that are too delicate to be put in the washing machine. Any heavy laundry such as linen and towels wouldn’t work.

Dolfi is more efficient than washing machines for small loads, in fact it uses up to 80 times less power, and 12-15 times less water every time you use it instead of switching on the washing machine.



If I’m not Traveling, How does Dolfi Help Me?

Dolfi is a lot gentler on your clothing than a washing machine, and uses significantly less power and water to wash them. It’s also much easier to use and quieter (in case you need to wash something at night).

When not traveling, Dolfi is a great alternative to hand-washing. You’ll have more time to do other things and won’t risk ruining the fabric with mechanical force of the washing machine drummer.

What Kind of Clothes Does Dolfi Wash?

Unfortunately, Dolfi isn’t meant for all kinds of fabric. For best results, make sure the item you intend to wash falls under one of these categories:


  • Delicate fabrics, such as silk, chiffon, lace, and so on. Any fabric that you’d be too afraid to put in the washing machine
  • Clothes that are tagged “hand wash only”, but that are not damaged from water alone (i.e. no leather!)
  • Shaped apparel, such as hats, corsets, dresses, or bras
  • Performance outfits, like figure skating and dance costumes
  • Swimwear
  • Activewear, such as yoga leggings, cycling outfits and other high performance training apparel
  • Garments with applications, such as buttons, studs, gems and so on
  • Children’s clothing


It’s not recommended to use Dolfi to wash any of the following:


  • Large or layered fabrics, such as sheets and towels
  • Heavy stains, such as motor oil
  • Jeans
  • Large knitted items

What Kind of Stains Can Dolfi Remove?

Dolfi is great at removing everyday stains, such as dust, blood, sweat, different oils, and many beverages including red wine, coffee, most juices, and cocoa. Dolfi is good at removing odor and will leave your clothes feeling fresh.


before and after


It’s also exceptionally good at removing chlorine and sea salt from swimwear, and doesn’t even need detergent to do so.

Some stains may need pre-treatment before washing with Dolfi, such as food stains that have a large particle size. For those cases, use a detergent enhancer or stain remover and give it a rinse before using Dolfi.

For really dirty clothing and heavier stains (such as motor oil), Dolfi isn’t recommended.


What Are the Different Types of Ultrasonic Cleaners?

Ultrasonic cleaners can be divided into several types based on their size and capacity.

Large Capacity Industrial Ultrasonic Cleaners

These ultrasonic cleaners have tanks that generate ultrasonic frequencies between 25Khz and 40KHz, which means they’re better suited for solid objects and machine parts. They can also be used for automotive parts and large musical instruments.

Table-top and Bench-top Ultrasonic Cleaners

Table-top ultrasonic cleaners can range in size and capacity. They often operate on a frequency of 40KHz, which is very versatile. The larger ones can be used for cleaning machinery, while the smaller ones are great for small machine parts, surgical instruments, optics and lenses, and so on.

Portable Ultrasonic Cleaners

These consumer-friendly devices are designed for every day, non-industrial uses. They often reach frequencies higher than 40KHz and can be used to clean jewelry, vegetables, clothing, glasses, watches, and the like. These cleaners are typically sold as a compact device without a tank. Dolfi is a pioneer of this category.


Dolfi is an innovative solution that utilizes technology to solve an everyday problem. It’s a perfect travel companion and a handy tool to own when the washing machine seems too aggressive or simply not available.

Dolfi isn’t meant to be used as a replacement for washing machines, but rather as a lighter, more portable companion. It can be considered a replacement for hand-washing.