I cleaned my service weapon at home today with my otis gun cleaning kit which I do love the pull through system. I had the hand gun to the point that the patches came out white. Tonight when I got to work I cleaned the shotgun and ar with the new M pro 7 kit that the office got and I was amazed at how much crap came out of the barrel. So I then cleaned the handgun again which again had just been cleaned with otis about two hours earlier. I was shocked at how much black crap I got out of the barrel with M pro 7 products. I think I have found a new cleaner for the deeper cleanings.