I think you can make a direct request to the guest via Airbnb for the charge. Hopefully they will fess up and pay up. If not, then you do have to file the claim to try and get it through your security deposit. Watch the deadlines though. I think there is a limited window in which to file a damage claim.
I have some very nice towels in my guest bathroom so it would bother me if some went missing. Plus I wouldn’t be able to buy the same pattern again And would end up with part of the set.
I have never had that happen, but you have twice so maybe it’s something in your area.or maybe it’s just bad luck. I don’t do it now, but if I had your issue I probably would start putting a list of prices in the guest room or guest bathroom that shows what the charges are for missing and damaged items. You may even want to have your guest initial it so you can keep a copy that they read it.
. Right now, I just list that there is a $5 charge for a lost bedroom key and a $25 charge for lost parking pass.