It definitely will work to remove rust, in fact (if you hook the wires up correctly) won't remove anything but rust. I have had good luck with it on old tools that have severe rusting. You still need to do a bit of scrubbing (I use a synthetic pad) but it is probably the best method I have found for cleaning tools without damaging the metal. Keep in mind it will only clean the surface, it won't put back what has already been eaten by rust, but it is worth a try. Take the advice and practice on something you don't care about first just to ease your mind, but it is relatively fool proof. By the way I first learned about this after reading an article that mentioned this was a method sometimes used by museaums to clean artificats.
