@Mary1211 If you are looking to argue the case with Airbnb, you will need to cite some law on the subject. I think you need to look into tenancy law and cases to determine how tobacco smell is treated. Your state has a website you could look at: https://www.mass.gov/info-details/local-state-and-federal-laws-related-to-tobacco
Health risks
If arguing the law isn’t what you want to get into, then you could simply, Twitter shame Airbnb into taking some action to address the smoke smell issue. The best angle to do this is from a Health perspective. Did you know that there are 70 known cancer-causing agents are in the cigarette smoke that coats a car, a home, and clothing? Walking into a room or sitting in a vehicle that smells like cigarette smoke is an indication that the environment is toxic. These 70 chemicals soak into fabrics and coat surfaces. It is not possible to remove them with regular “extra cleaning”, it requires something a little extra. Without it, all future guests are being put at risk.
By not supporting hosts to remove these toxins, are Airbnb saying they don’t care about future guests health? Many states, like New York, have introduced specific law called Clean Air Act to ensure employers and landlords are taking their responsibilities seriously in regard to second hand smoke. Are Airbnb not in support of guest health?
See how a case can be made? Here is an article you could quote: https://www.nomoresmokesmell.net/science-cigarette-smoke-smell/
This one also gives guidance on how to handle smokers and the clean up:
https://homelet.co.uk/landlord-insurance/landlord-lowdown-blog/article/how-to-identify-smoke-damage-...
Rules
I also recommend including a token warning in your rules in future. I have one in mine and, though I don’t expect Airbnb to honour it, it serves as a warning and deterrent. I display my rules framed on the wall as well as in the guest book. Here is what I say about smoking:
SMOKING POLICY
No smoking is permitted anywhere inside the property. If you wish to smoke, please use the garden outside the lower bedroom and close the bedroom door. Please ensure smoke does not blow into the cottage. Do not dispose of cigarette ash or stubs in the indoor rubbish bins or in the garden. An outside ashtray is provided. We reserve the right to charge a $250 instant penalty, plus extra cleaning fees and cost of future lost business, if the cottage smells of smoke or contains cigarette related litter.
Tech
Lastly, you may wish to install a cigarette and marijuana smoke sensor. I’m sure there are others now, but I recall seeing one designed for Landlords and Hotels called AirGuard or Fresh Air.
https://www.digitaltrends.com/home/airguard-smoke-detector-marijuana-tobacco/