Ultrasonic cleaners can be a good way to clean some of your small gun parts. However, there is some controversy over it. Ultrasonic cleaners work by turning high frequency sound waves into tiny bubbles the create a scrubbing action. They have been used for ages cleaning mostly jewelry and medical tools. Most ultrasonic cleaners also have the ability to heat the water or cleaning solution to further increase effectiveness. The controversy comes into play because some believe the ultrasonic cleaners create microscopic cracks in soft metals like aluminum. They can also yield somewhat destructive results to certain finished or painted parts.

Personally, I use an ultrasonic cleaner for small made of stainless steel. This is usually bolts, springs, triggers, and other things that are durable and/or cheap to replace. Springs will eventually wear out, but they are pain to clean by hand so I usually dump them in the ultrasonic cleaner. I never put things like slides, barrels, or suppressor cans due to the finish/coloring.

Most of these machines are NOISY! It may also scare pets like cats or dogs because they can hear the high frequency much better than humans. If you are going to purchase an ultrasonic cleaner buy one large enough to submerge all your parts.