Lots of people use bore butter as a patch lube, I guess it's OK for that but it liquefies at 80 degrees and becomes rock hard at 40. It offers no rust protection at all unless you just fill the bore so full as to exclude air, then you have a mess to clean out before loading. I know of one fellow who does that just so he can say "I use all T/C products" and no, he doesn't work for T/C.
Nothing removes blackpowder residue better than "the universal solvent", H2O, plain old water. After all, the residue is a salt and nothing dissolves salt like water. People insist on trying to invent some miracle concoction by adding a pinch of this and a smidgen of that and proclaim to the world "Eureka I've found it" but no matter what you add to water it is still the water that does the work. Hydrogen Peroxide is the worst of those additives since it is an oxidizer, do you want your barrel oxidized? Adding a dash of detergent to the water does help cut the patch lube so that the water can do it's work but beyond that, water, hot, cold or tepid is the best blackpowder solvent.
Once the barrel is totally clean, dry with patches and heat will help. Run pipe cleaners through the flash channel to clean and dry that important area. Once totally dry, oil with any good rust preventive oil. Before loading it takes only one dry patch to remove the oil and you're set to go.
Muzzleloading can be simple or as complex as you want to make it but I see no sense in making things complex and expensive when simple and cheap works better. ;D