As others have now told you, you don't remove the breechplug on a traditional rifle to clean the barrel. Everything goes down the muzzle. USE REAL BLACK POWDER, not the subs you used in that unmentionable.
Soap and luke warm water are all that are needed to clean the gun. remove the nipple and soak it in a small glass with soap and water. Plug the nipple hole, and pour some liquid soap down the muzzle. Then, pour in the water, and fill the barrel 3/4 full. Put your thumb over the muzzle to plug that end and shake the barrel up and down to mix the soap and water. Let the barrel set for 10-15 minutes. Shake it again. Pour out the soap water, and crud, and repeat, but this time, only put about 4 inches of water in the barrel. Now, use a wet cleaning patch on a jag, and run that down the barrel to work on the crud. If you really left the gun full of crud because you didn't clean between shots, you might need to use a bore brush to break loose some of the crud. The brush will not get all the way down to the breechplug face. You probably will need to use a scraper jag to get all the crud out, unless you are willing to let the barrel soak for several hours with soap and water, letting the soap and water dissolve the thick crud in the corners. Pour the stuff out the muzzle. Now put more water, and a bit of soap in the barrel, and this time, remove the plug where the nipple goes, and use the cleaning patch and your jag to force the water through the plug and out the bolster. Tip the barrel on that side over a bucket, or your sink, to catch the spray. That will clean out the flash channel from the nipple, to the powder chamber.
I repeat this process a few times, until my cleaning patches come out reasonably clean. They will always seem to have dark stains from the Graphite left on the steel in the bore. But both the water that comes out and the patches will be noticeably cleaner.
I flush the barrel with alcohol, so that the alcohol evaporating will remove the remaining droplets of water in the barrel. Then, lube the barrel for storage. I am having good success using Ballistol for storage, but I store the gun Muzzle Down, so that any excess oil drains out the muzzle rather than get down into the flash channel and congeal into a thick grease there.
If the gun has been stored for more than a month before its next use, I flush the oil out with alcohol, again, before taking it to the range, or hunting.
Those tips should get you heading in the right direction. There are lots of thread on this forum about cleaning guns properly. Look for them, and then read them. Good advice, here. Unless you insists on shooting plastic wraped modern pistol bullets, using smokeless powder substitutes, there is no reason to be spending money on the modern cleaning products. You need a good grade of oil, for the screws, and moving parts, but soap and water does the rest. You might as well begin by finding out how to save money on buying all that junk. :hmm: :hatsoff: