I've always been wary of the so-called home cold blue kits. I have an old Smith & Wesson Model 36 that had a pretty worn finish when I acquired it. I've polished off most of the remaining bluing with the idea of trying my hand at "rust bluing". If you aren't familiar with this process, it's the way bluing used to be done before the hot salt bluing process was developed. If done correctly it takes a good deal of time, but the results are a deep finish that is much more wear resistant than modern hot blued guns. I plan to start on the project after the first of the year.
NRA Life Member