I'm not sure what you mean by "the grates are on the out side of it." I assume you are talking about a regular outdoor BBQ.

When I clean our grill, I wash the grates, of course. If the briquets are covered with burned on drippings, they can be replaced. I got some at Target recently, better price than the BBQ store.

For my BBQ, the grate the briquets rest on is falling apart, but I'm making do with it for now. I'm sure it can be replaced at the BBQ store. As for the burners themselves, I take a pin and poke any of the gas holes that are clogged.

I'm sure there are other things to do, but that's all I know to do. If you know the brand, you might check online to see if they have a website with more info, or maybe you could even get a manual for it.

Have fun.

I heard once that you can take the grates out, spray them with Oven Cleaner, Easy Off, then put them into a big trash bag and leave them overnight. (outside)

Next day, hose them off. I've never tried this but it sounds like it'd work.

If the outside of the grill is stainless steel, they make a cleaner for that too.

take everything out - spray with easy off - inside, grates let sit - get gloves, brillo, hose scrub, rinse scrub/wipe rinse

I clean the inside of my grill using the incineration method. Basically I'll fire up the flame on high and lay a sheet of aluminum foil with the shiny-side down on the grate. Close the lid and in twenty minutes all of the former crusty bbq stuff has turned into a white powder. When the grill cools off, this dust wipes off easily with a rag or brush. Cleanning the outside depends on material.

I was given this method a few years ago which is beyond easy. Spray cooking oil on cold grill rack. Then turn on & leave on high, with top closed, for about 20-30 min. Turn off gas & all residue can be cleaned off w/a grill brush. Works everytime for me.

Turn the burners on high, let it get real hot shut the burners off and powerwash the hell out of it and bam good as new.

Unless the grids are realy gooky, you don't need to put anything one them. Just turn on the burners for a few minutes, and the heat will effectively sterilize them and burn off any congealed fat from the last time.