I like this idea except I'd hire three (all in revealing gear). Two work the bar & food. The third can "cover" if one of the other guys gets hired during the party. And, best of all, number three is your special treat at the end of the night. I'd be quiet/selective about telling guests up front, but allow the "help" to be as flirtatious as they want. You'll probably need to set ground rules where the "play" takes place. Sounds like my kind of party. Choose number three wisely my friend.