Yes it works but it takes time. I started by hand stretching and then pumping, just to stretch the sack. Look on newart.com/ forums for pumping info. Warm water pumping is good.
Then went on to wearing split collars(secretleather.com) Always warm up balls in warm water and the weights before putting on, use cocoabutter as lube.
Now I alternate between weights and pumping. I use a 12"x2.75" cylinder for length. Also hand stretch on a regular basis.
Like I said It takes time, so go easy, those bits are not replaceable.
cirus.