if it works for yer radio, it'll work on yer rust!
nother thing that works great on rust is phosphoric acid [trade name OxySolv for the stuff I've got rite now]. can be diluted w/ water. soak for an hour to overnite, scrub a bit, let dry then rinse w/ water. similar to what the chemical strip places use as an 'after-bath' to protect from re-rusting. I've just been doin the small parts from the side window/ vent frames. works great.
Bill