Has any one used the rear wheel bearing grease tool that is sold at Ecklers. And what did you think?

Yeah I bought one when I did my bearings,it works O.K. but,,it only puts the grease to the inner bearing not the outer.and if you pump to much grese into it you can blow the grease seals outthe instructions say to put 2 tablespoons of grease in nobody I talked to knew how much that was.Finally found out it is about 6 pumps with a standard hand operated grease gun,it is a simple tool ,just a piece of plastic with a grease fitting on it