Theft is a common issue in the lodging industry and I’ve had my share as well.
Professionally managed properties have contracts and stated deposits and credit card holds to successfully address this. Airbnb does not, and seems to manage complaints/claims on a case by case basis and requires proof, which can be difficult in a situation like this.
Some hosts have tried communicating with the guest directly, and that has met with mixed results.
Reviews are shaky ground all around.
Personally, I don’t spend time on a small item here or there.
I have modified my rates and I house rules to include breakage and missing items up front as a way to deter those issues, and I do not instant book. I screen each guest via messaging and read previous reviews before I agree to book.
The clarity mentioned in the last paragraph has yielded the best results for me.
Good luck!