The new smoker I brought home the other night has a giant layer of greasy gunk covering the bottom of the cook chamber. What is the best method of cleaning it out? I can probably scoop a lot of it out, but some looks pretty crusty. What's a good cleaner to use? Cooking grates are disgusting as well. Those i suppose I can do with soapy water. Just don't want a giant fireball first time I fire it up. Thank you.