Hello all, I would appreciate some helpful advice regarding a new Glock 22 and Glock 27 I just purchased. As you probably know, there is a brown (rustlike) residue on the interior of the slide. The armory dealer informed me this I should not clean this residue since it should be spread about the gun for some time (about 1000 rounds) before cleaning it. However, the police dept I work for recommends I clean the glock immediately after purchasing it. Who's right?