Another approach is to heat up the grill, then throw on some table salt + pour on a bit of white vinegar. Use a flat blade spatula to work it around, then lightly scrape it off.

It strips the hot plate back to metal (not joking).

So, no residue from previous meals is left.

Probably not be a good idea to do this on a hot plate coated with (say) teflon or similar. Did that once on a friends BBQ years ago, which stripped it back to the metal. Oops. Unsure what the coating was though. It definitely "wasn't there" any more afterwards. ;)