I tend to be with @Ward1 on this in regards to laundry items.
I like to use what hotels have set forth as the standard if I can.
When I go to a hotel, I can get TP and cleaning service should I decide I need it (I know that cleaning will cost me a tip as is customary) in the case of my Airbnb, should a guest ask for cleaning service during their stay, they would have to pay for the service.
a few other things a hotel offers is shampoo, conditioner and body wash refills
these all seem fairly low cost for the expense sheet to keep replenished, however, laundry service should always be an added fee for sure.
Landry facilities in any hotel will charge a per load fee as well as vending machine for the detergent. They also ask all guests to please help save energy by hanging towels for reuse. That seems reasonable to me.
I agree that most guests are very happy with what we provide with them but yes, we have had the occasional guest that just keeps asking for more and more.