Face to face is too confrontational imo. It's hard to get it right without offending the guest.
At least, it is hard for me to pull it off personally.
Regarding smoking for example, what I would do is send them a message like
"As per our house rules, smoking inside is not permitted. However, you can smoke outside on our balcony if you would like."
This is less confrontational, and is more likely (nothing is 100% guaranteed) to work. Suggestions are more likely to work if you offer them an alternative.
When you have everything recorded down in the Airbnb app like this, it makes it easier if you need to escalate it later down the line.