The question is really, "does this bug me enough that I want this fixed for the rest of my stay?" If yes, politely raise the issue as mentioned above. If not, put up with it and/or clean it yourself. But whatever you do, honestly and neutrally (i.e., not emotionally) describe what happened in your review. This sort of information is invaluable for people considering making a booking. As a frequent AirBnB user, I reason that if there are more than one or two reviews mentioning the same issue, it's probably not just a one-off problem.