Was that an electrolysis bath with the body?
Yeah that was a bit of a science experiment we decided to try.  Didn't have a big enough tub and had to put together a rigged up contraption to get it to work.  It was pretty amazing how well it removed the rust though.  It was down to bare metal after a couple hours in the baking powder bath.  Probably not the safest configuration, but it was effective.  We will do the same thing on the Pepsi cooler but will plan a bit more in advance on how to rig it up.