My advice is to 1) have guest to ommunicate via AIRBNB messages. Otherwise you will need to collect screenshots. 2) try to coax him into a clear statement like "unless you reimburse me, I will write a bad review. 3) tell him to go ahead and submit his reiview as he sees fit.
You may then neve see hiis review because you called his bluff.
If he reviews you can challenge thru AIRBNB. If you have EXPLICIT threat statement for AIRBNB review, they say they will delete his review.
AIRBNB told me that the following message from guest would not be explicit enough.
"Hello… my wife and I stayed at your Airbnb over the weekend. We wanted to let you know how our experience was prior to leaving a review on Airbnb. First the positives: we were pleased with the cleanliness, charm and the amenities. Also, the breakfast burritos were absolutely delicious and a very nice touch. Your place is nicely remodeled and the bathroom/shower experience was very pleasant.
Unfortunately, there were a few negative experiences that overshadowed the positive. The mattress was way too firm for either of us to enjoy a restful sleep. We even found some extra comforters and blankets and a partial foam mattress that we put under the sheets. Even with that the mattress was uncomfortable. We also brought some food with us to reheat and cook while we were staying there. Unfortunately, everything froze in the refrigerator. The eggs were frozen solid, the prepared oatmeal froze completely as well as the milk. This made it impossible for us to use our food as it changed the structure of the food and it broke the eggs when they froze. And of course the lack of heat and hot water that happened sometime during the night and lasted until we left. We were not able to shower or wash our hair, on which we planned doing. With the cold temperatures at night, the rooms got very cold very fast in the morning. We ended up boiling water to wash our dishes. Lastly on Saturday night we heard people upstairs talking, laughing & walking around we had to turn the TV up louder then usual to drown it out. Unfortunately, the full experience felt more like camping with noisy neighbors than staying in a nice Airbnb. We appreciate that you offered to give us a “discount“ next time, but at this point we would prefer a refund. We would consider staying another weekend at no charge if those issues were fixed! We wanted to give you the opportunity to make things right before posting that review, as we believe that everybody deserves another chance.