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

@Peter Morgan When it comes to renting with pets, there always be some negatives such as - damage to your apartment, disturbance to your neighbors, pet odors, etc.

For example, my lease has the following clause in it:NEIGHBORHOOD CONDITIONS: Tenant is advised to satisfy him or herself as to neighborhood or area conditions, including schools, proximity and adequacy of law enforcement, crime statistics, proximity of registered felons or offenders, fire protection, other governmental services, availability, adequacy and cost of any speed-wired, wireless internet connections or other telecommunications or other technology services and installations, proximity to commercial, industrial or agricultural activities, existing and proposed transportation, construction and development that may affect noise, view, or traffic, airport noise, noise or odor from any source, wild and domestic animals, other nuisances, hazards, or circumstances, cemeteries, facilities and condition of common areas, conditions and influences of significance to certain cultures and/or religions, and personal needs, requirements and preferences of Tenant.

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.

I hate cat odor.

You should also require this information is updated annually.You can still place reasonable restrictions on the animal, such as: Requiring a current (and annually updated) Veterinarian report on the health of the animal, including vaccine status; current appropriate local licensing of the animal if required in your jurisdiction; require the animal be spayed or neutered unless contraindicated by the Veterinarian; require the animal to be in a carrier or on a leash when in common areas of Multi-Family properties, particularly elevators or hallways and stairwells; require tenants to clean up after the animal in common areas and/or within their unit, and prevent offensive odors from emanating from their unit; aggressive or nuisance animals (includes frequent barking that is NOT an alert by the animal) can be cause for removal of the animal and/or eviction of the tenants.

I think there is an odor to this.

Odoban is great for neutralizing the pet odor you must locate the exact source of the smells and saturate that area with the solution let it sit for a while and then extract the liquid.

Vaping causes a slight odor and film too.