Yes-but not gun screws. Leave them in the "tulebox" for rusted automotive fasteners. Or, corroded aircraft fasteners-you guys haven't lived if you haven't spent a day pulling carbon steel studs out of WWII vintage aluminum wing framework, or, even better, aluminum engine components.
I've seen a 50/50 mix of diesel fuel and ATF do wonders when a piston is stuck in the bore of a cylinder block, but, you leave the stuff in the bore on top of the offending piston, and don't really do much until you see some seepage past the rings. A swat with a rubber mallet every now and then. Not much else.
That can take months. It stinks, too.
Not sure how to use that formula on guns.
Best,
Ted
