HOPPE'S foaming bore cleaner quickly and effortlessly dissolves and removes copper and powder residue. Its superior cleaning formula does the work for you, no brushing or other Mechanical cleaning necessary. The color change effectiveness indicator turns Blue indicating copper removal or black indicating powder removal. Simply spray the foam from the chamber to the muzzle, wait 15 to 30 minutes for the foam to clean and then use a HOPPE'S brand cleaning rod and patch to remove the foam from the barrel.