Depends what you want to do to it, and how much of a hazard you wand to be!
Wire wool and Nitromors is a good combo.
Or for the lets get dangersious approach, a de coke wire wool drill attachment on a slow setting, although, full PPE would be preferred in that situation.
Shot blasting is good. Bead blasting is better. Unless you have powder coated wheels, then just set them on fire FTW!