I'm on the U S cleaner wagon. I have cleaned tuning caps, trimmers, tube sockets, knobs, etc in that thing. Basically anything I can get into the tank. Its also good for glasses, watches, jewelry and other stuff. Also empty brass for reloading, model engine parts and gun parts. You don't have to use water either, it can be a solvent but you have to be careful whether the solvent will attack the plastic parts of the cleaner. I found that you can put water in the tank, put the parts and solvent in a smaller container and let it float around in the water while you run the cycle. Works great.
One other thing, it will take the paint off a dial scale so be careful with that. Don't ask how I know that tidbit.