Well I tried two acids Phosphoric and Muriatic(Hydrochloric). Phosphoric was like trying to remove it with wet sock. Muriatic fizzed, bubbled, gave off stinky fumes AND TOTALLY FECKIN NAILED IT. For black hardware, it just dripped off leaving a very clean metal surface. I used a swap though and it only took a few secs of rubbing after a few secs of letting a thin swipe off it sit. I'd be careful though, I was getting the sense that it could eat the metal very fast so it was the kinda thing where I'd rinse in water before I was sure it was done. Thanks Afghan Dave.