Porcelain-Coated Cast-Iron Grate Maintenance

I'm reasonably familiar with maintenance of uncoated cast-iron - seasoning and all that.

I have porcelain-coated cast-iron grates for the cooking surface in my smoker. What is the best way to care for them? Should they be seasoned like bare cast-iron (I wouldn't think so). If not, then how?

Thanks!!!

Terry Farrell, Tampa Bay, Florida, USA