I like cold water to clean followed by WD-40 (the bulk 1 gallon can type not the aerosol can variety) to displace the water in traditional ML's. However in my Optima I do the following, Wet a patch with Butches Bore Shine, run down the barrel with the breech plug in several times, repeat, let sit for 15 minutes, run dry patches down bore till basically clean, pull breech plug, finish running wet or dry patches down barrel until spotless, clean threads with bristle brush, oil bore, scrub breech plug INSIDE and out with nipple pick and old toothbrush and pipe cleaners and Butches, put new never sieze on threads re-install plug, wipe down all metal surfaces, done. I don't like to pull plug immediately because it's really hard to get all the fouling out of the threads that always seems to get in there otherwise. Just my two cents.