What king of cleaning Drew?
1. baked on carbon?
2. grease build up?
These seem like 2 different animals - tho they both come from drips in our grills. There are some commercially available carbon strippers that can be had as liquids or sprays. ( Carbon-off..? Is the name of one if I remember correctly. ) But they do not work on any grease. So remove all grease first. Use Purple Power or - even hot water and Simple green is pretty effective. Check with a commercial kitchen supply hose in your area.
But, Good old oven cleaner - *IF* you are up-wind...does a pretty good job on both. But it is nasty stuff last time I used it.