I've tried it all when it comes to cleaning my gas stove top grates.
I've soaked and scrubbed and sworn (j/k, I would NEVER swear ;0)
those nasty grates over and over and when I'm finally done with all that they don't look much better...that is, until last week ...
BEFORE: Now that's just gross people.
I put the grate in a zip lock bag, sprayed some ammonia in the bag, sealed it, and let it set over night. The next day the gunk just wiped off like nothing... I'm serious!
Yep, it's pretty much a miracle.