It seems to me, that even if there AREN’T any hard and fast
facts re the situation, common sense would dictate that something
that implodes little bubbles in liquid (like blood) might be a
teensy bit bad for you. Ultrasonic medical devices are made
specifically for that purpose, but ultrasonic cleaners aren’t.
Why use something for something it’s not meant for, especially
when it might be dangerous?
I fear, however, that the longterm users are probably going to
stubbornly keep doing it, because they haven’t seen the effects
themselves, and I hope they stay healthy. I, for one, was told on
my first day of class never EVER put my hands in it, from all
three of my instructors. I’m going to believe them,
manufacturer’s instructions or not. It’s just as easy to go to
the sink, and why take an unnecessary risk? Thanks to all the
people who contributed constructively… as a starting-out
jeweller, safety is important to me.