The smoke permeates into everything in the place after decades of people puffing away. My parents had a rental house many years ago that this old man lived in and rarely left. He was a heavy smoker. When he finally moved out the entire house had turned yellow from the smoking. I don't know what they had to do in order to get the smell out but it was a lot of stuff.
I love the death threats things, it's crazy how seriously some people take it.
That sounds horrible about the house. I had a truck once that a smoker had owned before me. I didn't realize it at first, but as soon as winter hit and I had to run the heat constantly, the odor just wafted from the vents.