NO!!! NOTHING NEUTRALIZES BP FOULING!! IT HAS TO BE REMOVED!! Otherwise, it'll attract moisture and cause rusting!! I clean my filntlock by pouring two quarts of boiling water through it and let the water run out through the touchhole liner hole (a 1/4" threaded hole). Then I wrap a G.I cleaning patch over the end of a breechplug scraper head on my cleaning rod, and rotate it around on the face of the breech plug. I do this with three or four clean patches, until one come out clean and dry. Then I put another one on the scraper end, oil it, and oil the face of the breechplug before I put the touchhole liner back in.