When we bought our cottage, the paneled walls were brown with cigarette "crud". Like Aunt Smurf - anything with ammonia in it - like Windex, will cut that crud and have it running down the walls. I washed the entire cottage in Windex...LOL!
Regarding ozonators: yes, they will kill odors, but remember: ozone is an oxidizer. It works exactly like Chlorine or Bromine; which means it fades fabrics; can make the plastic insulation around wires brittle, rusts steel like crazy, and makes rubber disintegrate. And it's really hard on your lungs.