black tank rinser

Howdy all. I'm sitting here at a full hook up site in my new to me HitchHiker. This is my first outing in it. This one has the built in black tank rinser. My old one did not. My question is, how do you guys use your black tank rinser when at a full hook up site? I do have a separate hose I would use exclusively for the rinser, but there is only one spigot here and it is for potable water. What do the rest of you do? No sewer/dump available at home.