Hands out either a Bulletproof Vest, Bread, Meat (lasts 2 days), Gun, Medicine (A doc save), or Arsenic (Which would kill) to someone during the night. What clerk gives out is random.
As an easter egg role, yes. I would want at least 2 in a 20 man casual game. As a serious role, more luck-based gameplay is bad. He should sell guns too, btw.