It wouldn't even assure that they got a wolf out unless they either took a third vote to clean out the last team from the clue, or the last standing were eaten. I can see someone arguing for it, but it seems like a horrible move to make unless there's a clear reason to suspect there's still a wolf left, and not just a vague uncertainty as there is now.

I like the idea of finding someone trustworthy, though that leaves the question of who.