In my experience, “no means no” and “leave the attitude with your clothes” are about the only hard and fast rules you need.
It’s good to provide the equipment you need for safer sex, but if you make it into a RULE you wind up having to enforce the RULE, and it’s a lot simpler to just accept that these are adults who get to determine their own acceptable levels of risk.
In my younger days I tried to organize a few. What I found out is that everyone is into the idea, but you’re lucky if one in ten of the people who say they absolutely, totally, without fail will be there even show up. It’s amazing the number of flat tires, sudden visits from out of town friends, and cases of food poisoning that suddenly occur when you schedule an orgy.