I recall seeing a show once where they talked about the BP silo shoots. The guys would take a spare cartridge, drill the base out and thread and install a hose. When they'd shoot they would insert it in the chamber and blow through it. The idea was the moisture in their breath would soften the fouling in the barrel. People think I'm nuts, but after every shot with my flintlock I blow down the barrel. No idea if it works, just a habit I got into.
Remember, shoot straight and shoot often.
Good... Bad... I'm the guy with the gun.