On the phrase,"w(h)et your whistle," I first was told of this by a friend who was writing her master's thesis on gargoyles and grotesques. In her research, she found references of medieval mugs with gargoyle whistles used in taverns in Germany. I have spoken to some German tourists at my craft shows who are familiar with whistle mugs (depending on what region they are from.) I have also heard that when harvesting wheat with a scythe, when sharp, it would whistle as it was swung through the air. When it began to dull, they had to stop and "whet their whistle." I have always trusted the info given me by my thesis-writing friend, though. This was research done in a university library. I could get a copy of her thesis and look up her references. Any comment??