Quoted from hailrazer:Steel wool and soapy water will do wonders. If that doesn't do enough then vinegar or Evaporust soak.
I used to do steel wool and vinegar. I go straight to evaporust soaking now and deal with any little details later. It's a miracle worker. I've tossed a few sets of legs I'm certain evaporust could've saved now that I've used it a bunch.