Seriously: try RB-17.
It makes cleaning a corrosive-primer or black powder cartridge gun like just cleaning a regular gun. It works really well, and it's a gel, so it doesn't get into the action like a liquid does.
I am not paid by them. I've never even bought the stuff: I've gotten samples of it from a range where I used to be on the board of directors and I've been really impressed. That range was 1000 miles from here, and I have zero vested interest in promoting RB 17, the range pro shop there, or anything else.
When I run out, I WILL buy some.