But if you were to use a condensor diaphragm and you jack the voltage difference up across the diaphragm and back plate, the electric shock it would give your knob would be a pretty good contraceptive!!!
CAD makes a mic that seems perfect for this application, the 22. We affectionatly call it the Dildo mic. It has a more contoured shape that a 58 and includes an on/off switch! Although I've never tried it myself, I've caught Col_Forbin giving it a knowing glance!