Toss a capful of Simoniz Nu Finish in your media, let it run a half hour before adding brass, add brass. Run for a few hours.
The red blotches probably means you left the brass in the Lemi Shine a tad too long. The citric acid that cleans so well also can leach either the tin or the copper out. I can never remember which one.
you can keep your gun. Period.