I dont know anyone that has done it and it worked but I have heard you have to do it for like an hour.
I hear it takes.hours just to pump 4 oz. If you want my opinion BABIES ARE THE BEST PUMP :-)
Also I had three different pumps one I bought one from the hospital and one from wic ALL of them didn't work I couldnt even get it going lol
I was told to do it for like an hour and then you rest and do it again. It also is supposed to cause longer and more painful contractions. Too much work for me