@Madeline28 I consider my apartment to be smoke free and I have no smoking defined in my rules... However, there is no way I (or Airbnb hosts in general) can 100% control the environment, i.e. can stop someone from smoking or doing whatever they please in my apartment when I'm not there. Case in point- this weekend I found cat or small dog poop in a bedroom closet of the apartment that has a NO PET POLICY. I guess I need to now add to the listing, "If you have a severe pet allergies, please do not reserve this apartment...".
This guest said they had an "extreme smoking allergy". If I had an extreme ailment, I would stay at a hotel where management could switch my room in a second, especially if I was traveling with friends/family. I would not stay at an exclusive Airbnb.
I accepted responsibility when I paid to have every surface of my apartment deep cleaned to include washing the walls with a vinegar mix, having all of the rugs and couches professionally cleaned, and changed out the air filter multiple times. I consider myself sensitive to smoke (but I am not allergic) and I cannot smell smoke inside.
I came to an agreement with the guest to refund half. My personal case is closed. Now that I have become more aware and have updated my listing accordingly, I am better prepared as a host (for the next time : ).