On the milsurps, we use degreaser to get that crap out of, and off of, the guns. I last used "purple power" degreaser which you can get at Walmart. Put barrel in a coffee can or bucket, and funnel/surgical tubing or a turkey baster in the chamber, and dump HOT water through it, followed by some purple power. More HOT water, then go to it with the Hoppes, dry patches, then whatever preservative.
RR