I’ve used UCs professionally (lots of rules) and at home (no rules 😁) for many years. Always with water based (aqueous) detergents of commercial grade through whatever was handy. Some other units at work were very costly and built to be “explosion proof” and used acetone. These were production (vs maintenance) units and were in ultra clean requirements for aerospace manufacturing. Explosion proof meant the fumes of acetone and the electric sources were isolated from eachother, with separation and nitrogen isolation. Many beauty salons just use acetone in an ordinary UCs to remove nail polish (fingers still attached 😁). All that said, I’m curious if anybody is using non aqueous solvents (acetone, mineral spirits, kerosene/diesel) in their UCs, heated or not?