Another way to structure it would be, for example, $50 off review special with $50 off a 2ed visit after the review is posted. Small discount up front to catch the eye of guys. do it. If he was happy with the visit, the extra for a 2ed visit might get him to actually write the review.
As I said, be creative. No right or wrong way to do it. Just remember what others have said. Many, if not most guys will never post that review.
I, BTW, wrote you one without you asking for it, or taking the Review Special, and I don’t regret it.