Lol yeah something most people don't know.
I disassembled my rifles, placed all the parts in a settub, covered with hot water and poured about 4 cups Simple Green in. Let it overnight. Turn on hot water while draining the old cold, and let sit for a few minutes again. Removed each piece while running under hot water and then sprayed them with WD-40 and placing them on a cloth. Completely cleaned of the stuff. Note I also complete broke down the bolt.. Not just removed it.
This took all the cosmolene off. It was painless and the Simple Green did all the work overnight. The WD-40 is basically to displace most of the water not really to protect the parts. I then clean, polish and then lub and protect them with Fluid Film... Or whatever you wish to use.