I like to use this on really thin sheet metal parts (like radiator tags, headlight buckets)too, as it doesn't remove metal or iron oxide, it replaces it on the ionic level. It doesn't plate, but it is really simple to use on any rusty part (steel or iron). Won't do aluminum or brass/bronze, ferritic based only. You can get really creative with how large and complex a part you need to do as far as immersion is concerned - I've heard of engine blocks being treated to remove cylinder rust with electrolysis.
Just make sure the sacrificial donor piece is hooked up to the positive cable, the part to be cleaned is hooked to the negative side, or your part might dissolve before your eyes.
You can find information online from several sources - really cool to do this -
Regards,
Steve