For the plastic fouling especially I have had pretty good luck spraying Hoppes Elite gun cleaner or Outers Nitro Solvent down the barrel and letting it sit 5-10 minutes. Then spray again right before scrubbing. Then taking an undersized bore brush and wrapping until it's a tight fit in the bore it with either the copper (or steel) mesh scouring pads from the dollar store for a scrub out. Scotch Brite pads around a brush works good too. Other solvent types probably work well too. The method is more about the mechanical removal of the plastic. I use the same method to remove leading from slugs too. I try not to use power tools unless there is rusting. Just my 2 cents worth. Good luck to you.

Last edited by sixfive; 09/23/19.