SFH Househack - Shared Bathroom Addendum

[Pat Tobin]

I have a six bedroom (househack) SFH where I rent out 4 of the rooms. Two of the rooms upstairs share a bathroom and I made the mistake of assuming that somehow, the tenants would figure it out amongst themselves to take care of it. I've had a few tiffs arise from each of the tenants. One of tenants takes, in my opinion, normal care of the bathroom and the other prefers it to be absolutely spotless and doesn't seem to grasp what he was getting into by sharing a bathroom. It turns out the only common/shared area of the house that I don't have an addendum for is their bathroom! I don't want to force either tenant to keep it spotless everyday as that seems very micromanage-y and overkill. Does anyone have some ironclad and logical rules that you have successfully used that I can add to an addendum to make their lives as well as my own easier?

Thank you in advance.  I love this forum!