@Adrienne174 This is one of those "You can't have your cake and eat it, too" situations. If you want to rent out 2 rooms to unrelated guests who have to share a bathroom, and you want to get good cleanliness ratings, then you can't also leave for long periods of time and not monitor the bathroom situation.
There's a few things I can think of that might help. One is to make it clear in your listing info, as well as when guests book and when they arrive, that as the bathroom is shared, guests need to be respectful and clean up after themselves in there. You could put a nicely framed reminder on the wall in the bathroom. Make sure there are cleaning supplies available to guests and even show the ones who don't "get" it, how to wipe down the hair on the wall and the floor of the shower, etc.
Realistically, a guest who books a place knowing that they are going to be sharing a bathroom with another guest can't really have high expectations for the bathroom being spotless all day, but still, they might mark you down on cleanliness. So you should make it clear to guests how often you clean in there, and that it's up to them to clean up after themselves the rest of the time.
Maybe you have a retired neighbor who would take on the job of coming over to do a bathroom cleaning once a day if you want to go out for the day, for a bit of extra income?
You could also reconsider not renting out both rooms to separate guests, but put both bedrooms under one listing- rent them as a unit, so friends or families can book both rooms. Then they aren't sharing a bathroom with strangers, and if one of them is a bathroom slob, that's their problem, not yours.