I by no means was suggesting that anyone should wash a pipe, but it was dropped in a full sink full of dishes and scrubbed like a coffee mug. I posted a thread on it months ago. It didn't make me happy, but it survived. I realize that wood is a tricky bugger, and pipes aren't designed for water. But, I wouldn't write it off yet. I have no idea whether rice would help or not, but at least it would be doing something. If it were my pipe, doing something would make me feel better than doing nothing.
I can imagine that there are lots of variables on how the water will affect the pipe; the finish, the direction of the grain, the cut of your jib, whatever. I would think that worst case scenario would be the tenon to stem relationship. Or, maybe just cracking somewhere. But, I would find it hard to believe that just being left out in the rain would kill a pipe. If so then these surely are fragile buggers.