I only stay at Airbnb's that have at least some reviews. It doesn't take too long to determine if reviews are sock-puppet-generated or genuine. You have to actually stay at the property to write a review, which means paying for the stay since Airbnb process the payment. Obviously you can create wash transactions but the transaction fees would still be significant.

Another approach is to sent a question to the property manager. Invent some pretext to ask a question. I find that people trying to scam customers on the product also have poor customer service skills. So if I don't get a prompt, cogent and polite response, I move on..