Why dont you let people ask questions about accommodation and, if you have stayed there, the question pops up in your app. Option to reply.
Is this place near a main train station? Does this place have fast wifi? Does this place have a Westinghouse dishwasher?
People love sharing their views and they are very likely to be honest in discourse.
I suppose you’d only get crazy people in reply to queries. The crazies tend to crowd-share their views. However, on balance you’d only get crazy people asking questions. So likely they’d cancel each other out.