Hopefully this helps. The keg on the left had some chicken going, a wrapped up pizza stone was my diffuser. I had just put the chicken in and the marinade was dripping off into the fire, the stone didn't really catch much.
The 2nd keg on the right, had some spare ribs going with an adequate diffuser/drip pan in place. In this keg I also had a stainless steel colander that holds my lump and makes for an easy cleanup. I like to place a couple wood chunks on each handle as it extends my smoke time w/out directly burning the wood. I never noticed the blue smoke until I had them side by side.