Moly is hygroscopic and can draw moisture from the air. It's not a big deal to prevent, the simple fix is to simply oil the bore when you put in away. Run an oiled patch down the bore after cleaning is all that's needed. I shoot molycoated bullets in 4 varmint rifles and have not had any problems. One of the foaming bore cleaners is supposed to remove moly, but I don't know which one. An undersized bore brush with a couple of patches soaked with JB paste will scrub out most of it, use a bore guide and scrub back & froth untill the patches slide easily, then replace the patches and do it again. Repete till tired and then don't worry about it, but still use an oiled patch last.