Hot, soapy (Dawn) water down the barrel. let it soak for a few minutes. Drain and follow with a few wet, soapy patches, followed by dry patches until all moisture is removed. Then a coat of Ballistol patches. Clean the exterior lock with Moose Milk (Ballistol and water). Every three of four range sessions, remove the lock and clean the internals with a toothbrush and Moose Milk.
This is what I do with my percussions, and plan to do with my Kibler Colonial flintlock.