I've used my machine to get rid of smoke and pet odors.

If it's there, painters have primers they can use to (try to) cover the smell (the primers I know of have a heavy solvent smell for X hours and are not for pet or human occupied dwellings).You could offer two solutions (recommend air fresheners be used if they stay, AND (before move in) offer to let them out of the lease).

Although there are no tax advantages to giving stays to be auctioned, we DO get to support a favored charity without cost, we DO get to expose our PET FRIENDLY property to folks who: A) love Lake Tahoe enough to bid on a stay, B) have the money to win a charity auction, and C) love animals enough to appreciate a pet friendly property - maybe returning as guests. 

If your insurance company doesn't allow them then it doesn't allow them, unfortunately.If one of our owners is ok with the pet in the home, we require $300k in insurance liability coverage from the tenant with our company and the owner listed as additionally insured.

We also are very stringent on who our tenants are (no pets/smoke/etc.), and we have each unit professionally cleaned once a month or once every two months.

We have always bought existing construction and remodeled and added on using contractors, except for painting and flooring, which we do ourselves.But, I often fantasize about building the perfect pet friendly multiplex.  

Option B) pay a one time pet fee.

These are things like paint color schemes, keeping each property in good repair, pet restrictions, holiday decorations, rental caps and all that small minutae that goes into how you can use your property and what you have to abide by.Rules and Regulations generally DO NOT require homeowner quorum/votes to change.  

Other things to consider when attracting guests if you allow pets or not. 

If his family has grown (kids, grand kids, pets, etc) he may have different needs than he does now.