I use a mixture of odorless mineral spirits and some hoppes#5 solvent (although next time I will try a different solvent just for experimenting sake) and it works good. I always disassemble the BCG and drop it in the pan with the OMS mixture and then proceed to clean the rest of the rifle. By the time I'm done, the OMS mixture is a dirty gray color and a lot of carbon and crud has settled to the bottom. Take the parts out, scrub them some, wipe them dry, and oil them. And the best part, I can pour the OMS mixture back in the jug and reuse it next time, most of the crud doesn't go back in the jug but if some does it settles to the bottom and doesn't get poured back out next time. Its made cleaning my AR's easier, especially after shooting suppressed a lot.