Don't have much experience with leading, so won't comment on that.
Bought a gallon of Hoppe's #9 years back, still using it up. Couple of wet patches, let it soak for a few and repeat with a damp patch, dry and oiled. As might be expected, ball powders foul more than stick and they do so more than flake powders if one is pursuing reduced loads. Harden the lead a bit, raise the pressure and it's pretty much a zero sum game.
Boogaloo, paper patch still rules this part of the universe. It's a thinking man's past time to be sure, but when the light comes on it can't be beat.