Yes, I've heard of the cream, I guess it's like acid etching........were you mask out the pattern or design you want then brush on the cream, let it sit for awile then clean off........I've never tried it though, so don't quate me on it......
Also there is the sand blasting etching, were again you mask off you pattern and blast the area with a very fine media.........I've seen small kits at wall mart for doing glasses and stuff.........I think it's worth checking out.........I'll probably give it a try just out of curiasaty