I'm sure some pipes have been nicked going in and out of racks, but not often. Most scratches and nicks and worse happen in handling pipes, mostly in dropping them. That's an advantage of blast and rusticated finishes that tend to conceal any minor damage. I'm not one who wants every pipe to look brand new. A little wear, a blessing of patina, makes a pipe more user friendly to me. After every smoke, I clean a pipe up and polish it a bit. I scoop out ash and clean out the chamber with a paper towel avoiding cake build-up. This retains the inner diameter of the chamber, eliminates the need for reaming ( I don't own a reamer) and reduces any ghosting.