You'll be lucky if they don't spill drinks on the furniture or carpet, or burn holes with cigarettes, etc.   

I generally discriminate against smokers of any kind.

Elderly tenant is a smoker and her car’s not running.

According to the Airbnb guest, the cigarette odor permeated every part of the building, including the foyer/common areas and the Airbnb unit.My Airbnb guests left me a scathing 2 star review, with one star for value and cleanliness due to the odor.

LOL, in college my roommate set the apartment on fire by throwing a lit cigarette in a trash can. 

We can assume the smokers are putting the cigarette butts in the drains and the wipes are coming from the parents, but people always want to argue that you can't prove any of that.

@David Crowley  Assuming there wasn't a previous smoker in the unit, charge them for cleaning. 

Must be a non-smoker.

The first tenant says their stuff smells like cigarettes all the time as a result (they live above the suspected smokers).The smoker denies they smoke in or around the house, but I’ve seen the cigarettes around the house and have reason to believe the complaint.The lease clearly says no smoking allowed in the house or within 30 ft of the structure.

My landlord even seen the husband walk out of the house with a cigarette in his hand.