I worked for an Electronics R&D house some years back. They had a tank with a bath of tetrachloroethylene liquid. The top of the tank had a band of refrigeration coils, and the bottom was slightly heated. It created a fog that would hang in the tank just below the lip. We would hold a basket of pcbs suspended in the mist and they would be cleaned in just a few minutes. Extremely cool technique. Alas, Tetrachlor would make labratory rats explode on contact, so it's hard to find nowadays. Stupid rats!