Keep in mind, the AC/Heating system will have the same smoker's residue as the interior of the unit. 

It has already been redone nicely inside/outside but I'm told it has a mild cigarette smell somehow.

Boom, you just spend 15 grand easy.Now a tenant moves out and the kitchen cabinets doors are falling off, the cabinets are rotted and the horrible yellow vinyl flooring screens 70's + 40 years of abuse and cigarette stains, and the kitchen cabinets are rotted under the sink and the counter needs to be replaced anyway.

In contrast, we had someone break into the washers and dryers on numerous occasions, a drug dealer, a pot smoker, a gal who had boa constrictors, and more issues in a month than my 9 SFRs had in a YEAR. 

Your SOL my friend, Brit has a good point there keep them in the unit smoke damage only really goes so far.Keep them long term and then bleach and paint all the walls when they leave install some new flooring if you have any carpet.Next time it's for rent the best way to determine a smoker, Ask to see the inside of the car they drive or their finger tips:-).

In 2011 my wife walked into small 1950s cape style house that reeked from 60 years of cigarette smoke and fell in love with the property.

Many people are more tolerant of pot than even cigarettes.

. $310 a month, single 53 year-old non-smoker, 6500 deductible.

I am always amazed though that when tenants are behind, they always seem to keep their cell phones on and cigarettes in their pocket

I could detect the smell in the bathroom, but it was not overpowering, and I couldn't detect any cigarette smell in any other part of the house.Confession time was over, I proceeded with inspection.