Thanks for the replies. I ended up using canola oil cooking spray. I got a little too carried away with the lump. I had one chimney going in the sfb and then I added another to the main chamber. Before I knew it, the temp was probably pushing 325-350 (I think the manual says not to go above 400). So I shut everything down, and the temp finally got below 300. I used an after market thermometer. I had my wife pick it up for me at Wally World today. It was $15. I tested it in boiling water and it measured at about 200 deg F. Not perfect, but after doing some searching, I discovered pickins around here to be pretty slim for grill mounted thermometers.