Mine on mmy gas stove are black iron. When thery get really dirty-greasy, I put them in my dishwasher. Works for me!

Put them on you're outside grill on high for a while, it will burn off the gunk build up.

I clean houses and many have the cast iron grates on top of the stove. I use a green scrubber with Weiman Stainless Steel cleaner. Give it a scrub here and there and wipe. Never have a problem with them. They'll look great.

mine were black originally, I put them in dishwasher every 2-3 months - just make sure to take them out and dry them well quickly - do not leave in the dishwasher in the moist condition - to prevent rust; in between those 2-3 months I just scrub them lightly with green or blue scrub pad when I clean the stove top surface

Don't they rust if you put them in the dishwasher? Doesn't it fade the black color?

take them out of the dishwasher as soon as the wash is done, - dont leave them in the washer. Dry them out - air dry, towel or set them in their place and turn all burners on for few minutes. Mine are three years old, still black and no rust

Thanks, Jollyrd. I'll try this!

have you had a chance to try it and what are your results?

mine are cast iron, and i put in the dishwasher by themselves with no soap.
Then take out and dry with a towel as soon as cycle is done

For a really deep cleaning, go to any grocery store and buy a bottle of cheap "Sudsy Ammonia". Pour in a non -reactive non-metal container, add the stove grates and let soak overnight. In the morning, all the gunk will slide off. Tjis works for me.