But either way, if that neutralizer helps, then yes, you could try to apply Zinsser or something similar to lock in and seal the odor should the wood itself be strong enough and not 'soft' however you have some other options....

Now that they are gone (strange folks), there is severe cigarette smoke odor concentrated in one of the 2nd floor bedrooms, also affecting the hallway.

The only trouble we are running into is many times the chain of title is fouled up so the bank can not provide clear title.

During this time, the property should stay vacant.The property should then be checked for odors or staining on walls or sinks etc. and recleaned if necessary.

Are reptiles any more risky to allow as pets in terms of damages or odors?

From living in the constant state of either rain or 100% humidity - potpourri and other odor cover-ups can't hide the mustiness.

Neighbors started calling about odor coming from the home.

We mopped the slab and walls with  white vinegar, gallons of it, several times, to neutralize the odor, then washed everything down with TSP, then used original Kilz over the worst areas. 

Have you tried Odor-Xit? 

Cleaning is as simple as bleach and water or a pet odor remover like "Nature's Miracle".