Personally I'd expect there to be some tricks of the trade involved. I've seen people use an ordinary general purpose ultrasonic cleaner of about 1 or 2 litres capacity for cleaning mechanical watches and electronic circuit boards, and it appeared to work satisfactorily, but they were using chlorofluorocarbon solvent as the cleaning agent. I doubt you could do that now, and if you could, you wouldn't want to put a claggy carburetor in the stuff and get it dirty.
