I don't think it has been posted.
Listen to the cry of any machop (Pokedex counts too)
Test results:
I listened to my Machop's cry, used the coin case, and it said this:
Coins:
which move?PP of
Use by water to
fish for POKeMON.
...It didn't reset, it just teleported my pointer up to Old Rod. I keep pressing Coin Case and it keeps saying "which move? PP of".
Edit: Oh wait, I think I might have been using a Gameshark code for infinite coins. I'll post when I fix it and test it again.