There is a man named Chris Derubeis. He specialized in grinded metal art.
Other people do this as well, but I've never seen it as unique and beautiful as Chris's work.
He won't tell anyone the chemicals he uses to get that look. But I've been experimenting, and I can get a similar look with candy-paint mixed with different kinds of reducers. Some reducers are eaten away by acetone, some aren't. Using this, I can paint the piece how I like it, then throw acetone on it, while it eats it away I light it on fire when I like the look of it, and it burns up the acetone thereby locking in the acid-eaten sort of look at that moment.
Once I resume this project I'll start posting updates.