Originally Posted by Maride
I learned this here and it worked beautifully on mine. I got a huge ziploc kind of bag and poured a little ammonia (about half a cup). Put the dish in and close the bag for one or two days. The next day pour the ammonia out and rinse the dish. The fumes of the ammonia clean the dish.
you can do that for grill grates or the grates on the gas stove. just keep it outside,while it is doing it's magic...!