Gun Scrubber is what I used in the army. Now I just use Hoppes 9 or CLP for cleaning. That Gun Scrubber was AWESOME when cleaning a SAW, especially after several thousand rounds, but a can only got two cleanings out of it. It was okay on the plastic on the SAW, but it would melt other plastics and would dissolve the rubber ACOG covers.
That was when a guy brought his pressure washer in. It was found out that very hot water and shaving cream actually worked really well. But hot water will do exactly the same thing as the solvets will --strip all the oil off making rust easier.
Plus, oil builds up in the surface of metal. Metal is also porous. Too much deep cleaning can and will cause parts to become brittle over time. I've seen an M4 bolt fail from the inside out from this. That was when our unit stopped doing the white glove test years ago and switched to a CLP only policy, and having "dirty" weapons was okay.
So if you only do a deep cleaning every so often, a can of Gun Scrubber lasts a long time. But a soak in hoppes works real well too, and it won't damage the metal.
At NTC they also had this big bay for cleaning weapons. All weapons. They had these parts cleaning sinks that sat on top of 55gal drums and were the same thing that you'd find in an auto shop. They use a parts cleaner, but it smells and feels a lot like mineral spirits. I'd think that would be a better choice than all the above for deep cleaning. You could put your whole rifle in there and hose it off with the stuff, blow it off with compressed air, and then clean it normally, but much easier, espeically for the machineguns. It didn't hurt the plastic, but I still took it off.
If you have an air compressor, you can get an engine degreaser wand for it that I bet would work really well with this stuff, and then use the air to blow it off.
