I bought a jar which has a small basket made of plastic in it. In that jar is a black powder cleaning solution. I take the breech plug and nipple out and put them in the basket then dunk them in the jar while I clean the barrel. I have two nylon brushes. One large one for the breech are of the barrel and a small brush that fits through the nipple part of the breech plug and lets me scrub the thing out real good.

After I have ran the brush through all of that I use Q-Tips that I dunk in cleaning solution and scrub the inside of the breech plug out until they come out clean. It really does not take all that long once the breeech plug and nipple have soaked a while....