I get the Flitz out using a Qtip, and I've been using it for about 22 years on my Glocks and have never had it abrade anything. I think it's not abrasive enough to do any damage to the frame, although I don't apply it directly to the plastic parts. As to a coating on Glock parts, Calreb are you talking about the copper color anti-seizure coating? I let that wear out by itself and don't try to remove it. If your talking about the Tenifer finish, I can tell you from being a Glock certified armoror that coating goes down into the metel itself and no flitz type polish can or will ever remove that coating. Even if you managed to polish off the black oxide outer coating, the tenifer finish would still be inbeded into the metal. And, unless there has been a change in parts/coating since I last certified (09/08/10) the other metal parts like the trigger bar, connecter, firing pin safety, etc. do not have a tenifer finish, and polishing them will not remove any metal or any coating. You are correct about the slide channel, polishing it doesn't make the trigger any smoother, but it does keep the galling down, you know the scratch marks you get on the four metal contact points the slide rides on? After polishing those points and the slide rail channel before breakng in my Glocks, I never get those. Galling can lead to the slide going slower, which on rare occasions can lead to a jam. Again, I don't get those due to the polishing of the slide rail channel and the four frame contact points.