No pump w/ Uli thing=no confidence

I am just wondering if anyone has had gains just using the uli thing, or beleives that the uli thing used alone will give gains?

Also,does anyone get a pump from using the uli thing?

I have built myself up where I can get/take alot of pressure with the uli thing,and be bigger in girth in both the head,and the shaft.But when I take the uli thing off,there is not pump affect.
This really destroys my confidence in this exercise,because I hear about people getting pump affect(being bigger than usual),and yet I have NEVER had a pump.Also,I dont know why,but Its basicly impossible for me to jelq or uli.I can do the motion,but its like I am moving no blood.

I really need to give squeezes a second try,but what are you guys thoughts on the uli thing issue.