EdP
WKR
For blackpowder: Water will suffice to disolve everything in the powder residue. Warm water and a little surfactant (soap) will help the residue disolve easier and a warm barrel will dry faster. Alcohol in the water will help it evaporate faster and aid in drying once clean. A breechface brush or scraper helps get the cleaning solution into heavy deposits at the breech. There are any number of cleaning processes that use these facts and they all work. No special BP cleaning solutions are needed (Hoppes, etc), although they work fine too. I don't see any advantage in using anything more aggressive than water with some surfactant and alcohol. It is very hard to wear out the barrel of a caplock or flintlock rifle from shooting. You are more likely to wear it out with overly aggressive cleaning. About 10 years ago I sold a flintlock rifle that I had put over 10,000 rounds through and it was just as accurate as when I got it brand new.