Here is what we use for regs and small parts cleaning. The ultrasonic machine is filled with plain water and a very small amount of Dawn (to break the water tension. We use glass containers filled with 2 mixtures that are placed one at a time in the bath. The first solution is 50% RO water and 50% Simple Green 13406 Extreme Aircraft and Precision Cleaner from Amazon.com (regular Simple Green leaves an nasty smell on some plastics).The second treatment is 50% Vinegar and 50% RO water. After those 2 treatments the parts go through 2 more clean water (RO) baths and are then dried. This is a heated ultrasonic cleaner so the cleaning times are kept very short.
