I have been trying new ways of using lava rocks for the last few months.. lately I have been mixing them with the Charcoal and it is working great.. Today I fired the Q up at 7am It is 530 and it is is still at running at 235! I did not have to add anything else during the cook expect a little more wood. All the charcoal will but out and I can just shake the lava rocks clean.. I have never had this smoker hold that temp for this long..
On a side note.. it is easily the best brisket I have ever done.