Reason is that my cleaner normally does a very good job of cleaning my rentals, and this is reflected in many reviews, but then sometimes she does omit to do something (as I can verify when I check after her occasionally, I always find something that has not been cleaned properly when you look closely), or perhaps a guest is overly critical sometimes, and will comment that cleanliness could be better, but only after they check out or, worse, in their review.
I don't mind criticism if I get the chance to rectify it as soon as possible, hence why I sometimes think if I should ask them on arrival, or if it will just make them think that I am not confident in my cleaner and they will purposely look for dirt in some hidden corner. Unfortunately I do not have the time to check after every cleaning, especially since my small guesthouse gets mostly one-night stays, plus we offer self check-in, so my guests normally do not meet anyone during their short stay. I always ask them via text to let me know that all is well when they arrive, to which they normally reply that they had an easy check-in and they love the room, but that's about it.. Just looking for some ideas and strategies from other hosts.
Also how does everyone handle stained sheets and towels with their guests, especially blood stains which do not always go away ? This is a recurring problem for me.