I've used the ospho stuff too. It works, but I really don't like the white residue. Plus it burned into my garage floor. As for the Easy Off, lye is the ingredient that makes it work. I used to get a kids pool and pour several cans of Drano in there. Put your parts in and wait a day or so for the paint to just fall off the metal. Can't find lye based drain cleaner anymore for some reason. I guess no one makes their own soap anymore.