When I was a kid, my dad gave my brothers and I some bricks and told us to scrape out the iron bottom plate of an old oil furnace with them, to remove the rust, etc. We thought he was nuts, but arguing with him never went over very well, and of course it worked like a charm. Then we washed it out and used it for a campfire griddle. You could do about 20 pancakes at once on it. The brick thing worked very well.