I have never done this, or read about anyone doing it. But it may be easier on your shoulders (injury?) because its done with a close grip.
arms by your side
arms out infront of you, like a front raise
your arms out infront of you like you were doing a skull crusher but standing up.
arms lowered but you keep the same angle, now your in a basic bench position.
Shows basicaly that bench is a heavy front raise with a extension at the top, of course you use your chest and the lift is much smoother than my picture but thats just to show you shoulders main function in getting it off your chest.
So, in theory, the lower you touch the barbell on your chest, the more shoulders you are useing to get the bar off your chest.
So, you could try takeing a close grip (easier on your shoulders), and bringing the bar down as low as you can to bring delts into the lift more.
Like I said, Ive never done it, but it will definatley hit your shoulders hard, and the way its done (elbows tucked, low bar bench) should be easy on your shoulders.
EDIT: its a assistance exercise, reading over it sounds like im telling you to change your bench form to it, so just thought id say.