Several years ago my brother and I ran a gun refinishing business. We attended a very large machine gun shoot as venders. Mainly did military firearms and Lots of them quickly due to BATF rules and the fact guys didn't like to leave machine guns laying around. We had to clean firearms very quickly and I do mean clean as parkerizing will not stick to oily, dirty firearms. We used heated Sodium Hydroxide from a company called Brownells. When done after several 12 hour days we disposed of that solution. But before we did we'd mixed it with mild acid solution call vinegars to adjust the ph. This neaturalized the solution so it didn't kill the bunnies, yeah like they were going to make it on a machine gun range. Poured it through a cheese cloth filter to remove greasy solids. Think about it guys, how does industry get rid of chemicals used to clean, pickle, etc. metals?

Six volt guy living in a twelve volt world