It's only used as a visual indicator in the factory to check that the rails line up in the slide properly. It's not going to "break in" anything. Copper is very soft compared to the hardened Rockwell/C64 of the slide and the steel rail of the frame. It's proper use is to provide a electrical connection in conduit for a proper ground. I use it on my auto battery for a good connection and prevent corrosion, it's a conductive type of grease. Don't waste your money on it, buy ammo!