Flitz is awesome stuff. I used it on my Gerber Mr. Pinchy in the mid 1990's and I've never had rust on it, and I use it every so often on my carry gun and have had a good result with that as well. I agree with SteveC though to try toothpaste or a mild abrasive first. If you use Flitz on a brushed finish it will become a polished finish but it surely will remove the fingerprints.