Whatever you buy, think about what you will do with the waste that you generate. And, as others have already mentioned, don't forget about any fire hazards.
At our Machine Shop, we use Safety Kleen solvent in a cleaning tank. And let them take care of the waste that is generated.
But, we also use Simple Green with a lot of success, and another biodegradable degreaser called Hotsy All Purpose Tubmate, in a heated cabinet washer.
At home, I try and use the least amount of chemicals as possible.
