Of course the electronic stylus cleaners do not work through cavitation and could not possibly do so. You need a liquid medium in which to generate the bubbles. There is no claim that I ever saw that they operate by cavitation or that they are even truly ultrasonic. Somehow, that descriptor got attached to those gadgets, maybe because ultrasonic record cleaners are so in vogue. The Audioquest is said to operate at 480Hz, but I am sure there is quite a lot of variation in frequency from unit to unit, which is why I originally wrote "400-500Hz". My guess is they literally shake the dirt off the stylus and cantilever. The first time I used mine, to clean a well used Koetsu Urushi, a big gob of dust came out of the workings of the cartridge. Which made me think that one conceivable advantage of the electronic cleaners is that they may do a decent job of shaking out dust that is on the "top side" of the cantilever, the side closest to the cartridge body, which is normally not accessible for direct cleaning, unless you're working under magnification and with fine tools.
You suggest that Audioquest mentions using their electronic cleaner "wet". Where did you see that, and how would that work? (I'll look in the owners manual, which I have here somewhere.) I am not fearful of damage from the Audioquest; the cartridge structure is well designed to deal with the frequency range of its operation, which is audible as a 400-500Hz tone. And I use it for no more than 10-15 seconds at a time. I WOULD be hesitant to expose a cartridge to anywhere near the frequencies at which ultrasonic cleaners operate, which would probably be ineffective anyway without an aqueous bath.