My MIL was a chain smoker. She lived her last few years with my BIL.
He did his best to "contain" the smoke odor to her room - but it's still there in the house.
All F/Fs know the olfactory nerve (sense of smell) is the first to "go" - so, like the "old days" when you went to a pub and it reeked of cigarette smoke - - after a while you didn't notice it anymore.
Smell your clothes the next day, and Yikes!!.:(
F/F's have some spray smoke deodorant, affectionately termed "Fu-fu juice" - used a lot of that for a lot of years.
However, it simply *covers* the odor - with a different odor, which is supposed to be more pleasant.
Works pretty good for small fires - stuff on the stove, etc. - but no help (nor intended) for long-term, residual smoke odor.
Recalled a thread from Escapees HDT forum on removing smoke from (used) HDT cabs.
Most (all, lots) of OTR drivers smoke - spending lots of time for lots of miles.
So "chased" a few of those suggestions also.
Ozone generating machines - and extensive cleaning came up a lot.
One poster even uses an ozone generator in his MH, as he and his DW both smoke.
He claims visitors are amazed there's no smoke odor (of course maybe they're just saying that,LOL!)
He uses a generator from Air Zone -
Air-Zone Ozone Generators~
Another option is a group of products by "OdoBan" (maybe it's just more Fu-Fu juice) -
OdoBan~