I recalled my dad once doctoring the dishwasher racks with some compound and went looking. Home Depot was a strike. Lowes had some under the brand Re-Rack.
Trimmed off the cracked nylon coating, steel wooled the rust and coated with re-rack according to directions. Applied multiple coats and let dry overnight.
Has held up well so far--about a month. For the cost and time involved it would be well worth it even if it only lasts a few months but reports online seem to indicate better life than that.
Better to catch the rust early and keep your racks healthy.