I have no idea if that really is an accurate sound to a mic drop...but it worked so I went with it. See you Tuesday!
There shouldn't be any screech noise unless the mic got to close to the speakers or another mic, though there might be a screech after it hits due to the vibrations.
Mechanics of a mic drop. Hold it up for a second, the sound guy shuts off the power, then you drop it. If it makes noise, sack the sound guy.