Caryn,
I have greatly reflected on your predicament and now really appreciate that you were kindly reaching out for help.
I too have your same bathroom issues and hope I can ameliorate your worries.
Cat? litter box? Personal Stuff?
Don't sweat it.
Do what you want, do what you think is best.
This is the beauty of Airbnb - we are all adults making self-serving decisions amongst so many choices. As a guest, you have told me you have a cat. I as a perspective can choose to be fearful of the litter box and go elsewhere, can ask you about the litter box, I can choose not to mind, I can choose to mind but still make the reservation or embrace your cat.s
The other super thing about airbnb are the reviews. You don't have to disclose your litter box in the bathroom - your guests will.
Hopefully they'll say "Bathroom was neat and clean. There was a litter box in there, but i didn't mind because it was cleaned out."
Of just as valid they'll say "Litter box in bathroom could have been cleaner"
Through the reviews, your course of action will become clear.
As hosts, we all get mired in the details and the what-ifs, but we should remember the airbnb dream.
We are travelers, we are hosts, we are adults who can make choices, we are all on an adventure.