We had just happened to buy a couple of ozone type air cleaner machines a few months before the big wildfire in our area six years ago. We evac'd and luckily came home to an untact home, but every single thing we owned smelled like a charcoal briquet. Drapes, furniture,carpet, toothbrushes, every piece of paper in the house reeked of smoke. 24 hours later, we couldn't believe the difference. All noticeable traces of smoke were gone. That type of cleaner is not sold to consumers in Calif anymore, but disaster clean-up companies and car or RV dealers apparently have a waiver to use them. They are amazing. Still, I would try my darndest to buy an RV that did not have serious odor issues.
