This is electrolysis, a very neat process that can be done at home if you are so inclined to try it out. It's essentially using direct current electricity to cause a chemical reaction that otherwise would not happen. I have been procrastinating on another Electricity for Permies post and I think you just gave me a great topic!
Here is a
link that explains it better and more in depth than I currently can. I'm sure there are other folks around here that know more than me too!
*Edit Just saw Mike and Douglas already answered. Lol should have refreshed before making my post.
r ranson wrote:Some of those items are chrome plated. Wouldn't that remove the plating?
I don't think so. From what I understand (other correct please if I'm wrong) the process is converting the rust which is iron oxide back into just iron. So I don't think it would mess with any chrome plating. However one safety note I just read in that link I posted was to not use stainless steel as your sacrifice piece as it generates hexavalent chromium "which can cause severe skin problems and ultimately, cancer". So just use some other type of mild steel you have laying around. ALSO if you do try it out just make sure you're doing it where there is good airflow, because the process does generate hydrogen gas. It is not toxic or poisonous but it is very flammable!!