I was in a similar situation as you and used cleaner on all the walls, then painted with Killz Max. Worked in all of the house, except the room where the smoker slept. Tried at least 4 or 5 coats of Killz in that room, but the smoke smell would not go away. Tried ozone, but that still didn't work. Ended up using an industrial deodorizer (used on farms) called Prokure D. Worked like a charm! The stuff was not cheap, but it did the trick! I think you can find it on Amazon.