In my days in what is now referred to as the Financial Services Industry, it was generally considered that the collective noun for bankers was "a wunch of bankers".

A collective noun for masturbators? A hand? A grip? A bishopric(k)?

An old friend of mine always referred to multi-tracked recordings where most or all the instruments were played by one person as musical masturbation (his favourite example was Mike Oldfield's "Tubular Bells").

Pass me my old malaka cane, George, I'm sure he'll enjoy it!

Alan