We have an ultrasonic humidifier for the kids.
Inside, there is a place that a sealed water chamber drains into, it makes a little pool of water about an inch deep. At the bottom of the pool is the ultrasonic vibration device, which I think is some kind of piezoelectric disk. As you tun up the intensity, the surface of the water first begins to ripple, then forms a cone in a kind of standing wave, then it starts to generate a mist emanating from what I can only imagine is the focal point of the wave, where water is being atomized by the vibrations. If you turn it up to full intensity, a LOT of mist is produced, as well as a few water droplets popping off here and there in various directions.
Curious, I wanted to feel the vibrations in the water, so I touched the pad of my finger to the surface. This stopped the mist. There was nothing at first, and then there was a rapidly growing feeling of pain as if a widening needle was being shoved through my finger. I pulled my hand back and inspected my finger. There was no injury, and the pain subsided immediately. I tried it a few more times, very quickly. It was quite strange how the pain grows from nothing and gets more intense over time. 1 sec and it is uncomfortable. 2 sec and any normal person would pull their hand back. I imagine 3 seconds and beyond would be excruciating.
Thus I have no interest putting any kind of meat in an ultrasonic cleanser.
