Here's a quick post for you halfassed jewelry makers who love an interesting patina.  Check out Anvil Artifacts http://anvilartifacts.blogspot.se/2012/04/patina-recipes.html

I've already tried the salt and vinegar potato chip patina recipe with great success, but ruined the finish by using a scotchbrite pad on it (stupid me).

I've got a pair of earrings in the chips now...I'll take pics tomorrow after 6:30 when it should be done cooking.