I think you are fighting a losing battle in trying to avoid swabbing the bore for a patch&ball rifle between (multiple) shots.

In fact I would suggest you go take a look as some very fine rifled-musket designs (generally Enfield/Springfield) if that's your goal. They were designed for that very purpose--repeated/no-clean firing--and can be very accurate at longer ranges using the Lyman old-style/thin-skirt Minnie ball. [Ask any N-SSA shooter]