I use an aqueous based product line that is free of solvents, biodegradable, and works like a charm. Out performs Simple Green by a long shot. This product was developed primarily for use in military and industrial appplications. It has been researched, tested and the results speak for themselves. They even offer a parts washer.
Check it out @
http://www.hurrisafe.com/
I have been a satisfied customer for 10 years!
