Flitz and Barkeeper's Friend are both good. This one's not rocket science- you can use fine steel wool or a Scotch pad to clean 'em up pretty easily. Obviously to polish them up you'll want something finer but cleaning the rust off isn't too hard unless they're badly rusted and pitted.
BTW, there's nothing wrong with carbon knives, per se. Yes, they can be reactive and aren't ideal for cutting acidic foods but they can take a very good edge and are great for proteins. Most the most expensive Japanese knives you can buy are made with carbon steels like Aogami.
If we're not supposed to eat animals, then how come they're made out of meat?