I'll admit, of all the things you could hire a clown to do (like a store opening, birthday parties, or covering him in fake blood, giving him a plastic knife, and asking him to chase your kids around the backyard for giggles), hiring a clown to just hang out and drink was not something that had ever occurred to me.
Wouldn't it just be cheaper to dress one of your friends up like a clown, and take HIM out drinking? Cause a get the feeling hiring some random guy to follow you around and drink might get a bit awkward.
I've got a better idea: Why don't you ALL dress up like clowns, hit the local bars, and see if any of you can pick up any girls that night. That actually sounds like a riotous night.