OK, so now I see you're NOT supposed to use Stainless. And its not illegal to use it, its illegal to dispose of.
Why you should not use stainless steel:
Many people using the electrolysis method for rust reduction swear by stainless steel, stating (incorrectly) that it's not consumed, stays clean and seems safe. Stainless steel is indeed consumed when used in the electrolysis process, although slowly. The main problem with using it is the hazardous waste it produces. Stainless steel contains chromium. The electrodes, and thus the chromium consumed, and you end up with poisonous chromates in your electrolyte. Dumping these on the ground or down the drain is illegal. The compounds can cause severe skin problems and ultimately, cancer. Hexavalent chromate is poisonous. These compounds are not excused from hazardous waste regulations where household wastes are. These compounds are bad enough that government regulations mandate elimination of hexavalent chromate by 2007 for corrosion protection.