 It's a little bit stronger than just a powdered soap or something along those lines. I prefer to use something like a trisodium phosphate. And you can get trisodium phosphate where it's phosphate-free now. But it's termed TSP, trisodium phosphate. It could be Soilax, that kind of thing. And just give it a good scrubbing. It'll remove pretty much all the oxidation. You may have to scrub it a little bit with a scrub brush.