I've used a lot of different stuff over the years. I always thought that military rifle bore cleaner got crud off better than anything short of an automotive solvent tank, but supposedly has some serious health risks. Hoppes 9 is pretty good for removing carbon. Shooter's Choice and G96 have been decent, but not as good as Hoppes. I tried Frog Lube on my pistols and my new AR. In terms of function, I had no problems. Frog Lube worked good on pistols, however, I didn't think it did any good at preventing carbon build-up, and didn't as good as a Hoppes soak to remove it from the back of the bolt. I like Mpro7, and found it does clean about as good as anything, although a Hoppes soak is still likely to get more deep baked carbon off the gun (I also shot up that last of some Winchester "nontoxic" 223 that was really gunky and nasty). In terms of lube, I heard enough good things about Slip EWL that I decided to try it. It seems to work good - guns function smooth.
There a website called Fr. Frog's and he has a page on testing gun cleaning solvents and lubes. His was interesting. Google it.
