How I got my range grates looking black again after years of neglect

I did the same thing on my 1998 Viking last spring and the bag trick pulled off years of gunk that three rounds of oven cleaner never touched. I had been scrubbing with Easy-Off and a nylon brush and getting nowhere, then a buddy who works in a restaurant kitchen told me about the ammonia fume method and it was night and day. I used the store brand, maybe half a cup per bag with two grates doubled up, left them on the garage shelf for about 20 hours. Even the underside where the drips bake on came clean with a green Scotch-Brite and some Bar Keepers Friend after. One thing I noticed on mine was that the feet on the bottom of the grates had worn flat spots, so they rocked a little even after cleaning. New feet from the parts counter fixed that for a few bucks and made the whole cooktop feel level again. Agree on the paint too, I tried it on one chipped corner and the shade never quite matched, so I stopped there and let the rest show its age.

Tried a version of this on my old range last fall. Didn't have bags big enough for the grates so I tied a trash bag over a bucket instead, same idea. Fumes still did the job.

Question though, how often do you all do this? I'm thinking a soak every six months or so keeps mine from ever getting that bad again. Also wondering if the burner heads can go in the bag too or if that's asking for trouble.

I toss the burner heads in the bag with the grates, no problems so far. Just make sure they're fully dry before they go back on, I leave mine on a towel by the window for a day. As for schedule, I stopped waiting for the heavy stuff. A quick soak once a year and wiping spills while they're still warm keeps mine from ever building up like that again.

This is making me look at my grates differently. Mine have the dull chalky stuff too but I always assumed the coating was just old and done for, so I never tried anything beyond wiping them down. The bag idea sounds almost too easy. One thing I'm not clear on though, when you say shiny metal means the coating is worn thru, how can you tell that from a spot that's just still dirty? I don't want to soak and scrub and then convince myself I ruined somthing that was actually fine. Also does the ammonia smell hang around the kitchen after, or does it fade once they're rinsed?

Update: gave the trash bag over a bucket version a shot since my zip-locks were too small for the big center grate, and it worked just as well. Also tossed the burner heads in like one of you said, left them on a towel by the window a full day before putting them back. Question for the group though, does anyone wipe a thin layer of oil on the grates after a soak, or does that just attract more gunk?