Everyone who owns a gas stove, pin this!! It works! Mine were absolutely disgusting and I tried everything to clean them. It was so gross how much came off! Definitely the best stove grate cleaner ever.
Cleaning the grates on your gas stove. | Slip grate into a baggie with some amonia. Put bag in a glass bowl. Let sit 12 hours or overnight. Easy! [http://www.pinchingyourpennies.com/2011/10/i-saw-it-i-tried-it-cleaning-the-grates-on-your-gas-stove/]
DIY Eco-Friendly and Money Saving Scrubbing Cleanser
slip grate into gallon size ziploc bag. Do not put any holes in bag. Pour 2-3 T. ammonia into bag. Seal bag & let sit for 12 hrs. Do this overnight. Take grate out of bag in kitchen sink. Rinse the grate thoroughly and scrubb with a nylon scrubber.