I'm on batch two (making a nice dark ale w/ roasted grain), and I just realized accidentally destroyed my fermentation lock (it fell into the in-sink-grinder) when I made my first batch (after completion). I've just finished with the wort! I gotta pitch the yeast tonight, and no airlock! The LHBS is closed (open tomorrow afternoon)! What do you suggest? Can I rig one up with some supplies from the hardware store or something? Help!