They're usually called rust cure, or rust killer, and are at the auto parts store. Not something you'll want
your children handling, though. Besides it will stain your fingers purple, lol. It turns rust into a shiny black surface that will stop rust dead. I've tried aluminum foil, and never had any luck. My suggestion of the rust killer, was to stop the rust at the rivets, before the hole enlarge enough for the rivets to pop out from use. Totally different from aluminum foil, which would remove rust on the rails. a little WD-40
(sparingly) with #0000 steel wool will make the chrome shine in no time flat.,,,,BD