I hate to admit this - but some considerable time past, I got my
first ultrasonic cleaner. It didn’t do anything - I even put in hot
water, ran it for a few minutes with the recommended soap type stuff,
nothing happened, nada, nyet.
Finally someone kindly told me that when you put in a fresh batch of
water and cleaner, there are bitty air bubbles in the water, and
nothing will happen. So - if your sonic does nothing - do this: put
in fresh water, turn on the heater if it has one and wait a few
minutes until it makes happy sonic noises. Before that happens, it
isn’t capable of cleaning. Test with aluminum foil.
Stuff doesn’t clean well if it is in a plastic basket that absorbs
the sonic vibes.
My choice for a cleaner is some of the purple de-greaser that Sams
club and others sell in gallon bottles. I dilute it at about eight
parts water to one part cleaner. Pretty much all of it works to some
extent - the prepared cleaners from jewelry supply folks work really
well, but I can never remember to buy more so I use what is around.