I seem to be in the minority, but I hate the spray foam, at least the one I've tried. Gunslick I think. I just seem to get it everywhere. It does seem to do ok on copper at least, but no better than Eliminator. Actually copper is a very small problem in most of my barrels, it's the carbon that gets baked on that can be the tough one. Eliminator carbon remover, brushes, and if all else fails jb bore bright on a patch around a brush seems to work.