I use a 6" tube in the left front corner of my RT 590. There is a probe hole there for some fresh air. As Jim stated, light and let burn for 10 mins and then blow out flame prior to putting in smoker. The 6" gives me about 2-3 hrs additional smoke. I use either Lumberjack or Bear Mountain pellets. I "do" put them in microwave to make sure they are completely dried. 1 min, allow to cool slightly then another minute. Keep an eye on them as they can ignite.
Thanks for all the help! I can see it a little better in my head with the help ya'll have givin me. Imma give it a try and see what happens. Everyone said the food tasted great and could taste a small amount of smoke but heck... maybe it's just me but... I need that eat the dang smoke flavored plate it came on smoke!!