The right method also requires the key in tandem with this (if you can do it without the key I have suspicions the rewind mechanism is also compromised, but I really am speculating without seeing it); not a standard modus operandi, but often used with 220 film.
Originally Posted by batwister
I have my own question mark about the 67 discovered only a few days ago during a moment of mischievous boredom: that I can put the mirror up with the mirror lock-up lever and then trigger the shutter by screwing the shutter release cable into the mirror reset button (instead of the shutter release button) on the front of the body (!) This very peculiar quirk might have something to do with the factory-optioned multiple exposure facility. I was damned irritated to have wasted a frame of Velvia...