A second vote here for Butch's Black Powder Bore Shine :thumbsup: ! It emulsifies black powder residue on contact, and is non-toxic (safe for kids to clean the guns), and has a built-in drying agent in it to prevent rust.
I do a range cleaning of my rifle ( a cap lock) by pulling the hammer back to full-cock, and squirting some Bore Shine into the bore, then wetting a couple of patches and using my range rod with WORM, I pump the worm to make suds. Repeat this about 3-4 times depending upon how long it takes for the patches to come out white. The cleaner squirts out the nipple and cleans the entire ignition path when you pump the range rod. Then I take the white used patches and soak a little more Bore Shine in them and give the entire nipple area a good wipe to remove the black powder residue. I also wipe the hammer and the lock and any wood with powder residue. I've come back a week or so later to that cased gun and did my usual thorough cleaning job ( the usual water, pumping warm water through the bore, dry, oil, remove nipple and clean, etc.) without a bit of rust anywhere! In fact, since I belong to more than one club that shoots black powder, I've just did the range clean, and a week later I've shot and WON the match at the other club. You can't do that with water!
Just remember after oiling the rifle to store it MUZZLE DOWN on a piece of paper towel, rag, etc., so that oil won't lay in the breech or flash channel and cause an ignition problem the next time you put the gun into service. A dry patch to remove any excess oil, a couple of snapped caps at the firing line, and "Load'em up Cowboy" cause you're ready to make smoke!
Have fun and make smoke!
Dave