I know this is not a direct answer, but I have discovered some great cleaner called Carbon Killer 2000 (non haz low odor and outstanding in keeping my guns clean). Intended for cleaning out modern cartridge guns, I figured it was worth a try on the BP revolver.
Works gang busters. A guy tested all the cleaners some years back and using a Hawkeye Borescope found CK2K (my shorthand for it) worked by far the best. I don't generate copper so I don't need that kind of removal though I have cleaned it out of other guns using Boretech Copper and the CK2K to remove carbon layers (it will remove some copper just not its main intent)
Ok, the method I came up with is not in any instruction exactly. I have an eyedropper bottle with CK2K in it, I drizzle it on a nylon brush and run it through the bore. In the case of the revolver front to back of course and then I put some more on when the brush comes out in the frame and pull it back through.
Then a Wet 44/45 Cal patch which come out filthy of course. I just repeat until the bore is clean. About 5 cycles of that. I use wet patches to clean the powder blasting off the gun surfaces.
I use the same process on the Pistols. For the rifles I usually clean them at the range, a warm barrel works a bit better and I hate cleaning rifles at home for some reason (pistols ok). Carbon Killer recommends 5-10 time running through for a rifle. I put on CK2K before, run it through and out the muzzle, drizzle more on, give it 5 cycles of the nylon brush, then out the end again and follow up by a wet patch. If I have shot 50 rounds its about 5 cycles for that though of course they are not nearly as messy as the first BP Revolver patches.
