EWIS anyone ?

This stuff works great, and if you keep it in a plastic container with a lid, just submerge the parts in it for awhile. Since its designed to etch aluminum, its a mild acid. Diecast parts should not be left in it very long. Maybe 15 minutes. Use rubber gloves as it will dry your skin out to where the outermost layer will peel off. Additionally it took off the scum and tarnish that was stuck to the chrome on my hazard switch. I have found it will clean rust off small steel parts like screws too, however it pretty much ruins the solution for cleaning brass and copper contacts when you do that.