if its 'loose or clunky' that could indicate shoulder instability.. you may have some kinds of knots in your shoulder that can cause the muscle/s to weaken, hence your shoulder may hurt. To work these knots, you need to do some kind of myofascial release i.e massage.
If it is terrible for the rotator cuff then don't do it
just my 2c worth, from reading all about trigger points and muscle instability....