Baking soda.
One of the other online suggestions is to mix baking soda with white vinegar which would have a similar reaction, mixing acids and bases.
I'll probably end up trying all of the above, it's cheap and these burners need the help. There are 6 of them, maybe I'll run some experiments.
But first they're all getting a power wash and a soapy bath with a grease-defeating soap like Dawn.