Most jucos have "wants to play" preference. That's the reason for difficulty. If you want to redshirt a juco, you have to play with fire a little bit.
In my opinion the best way to do it, is to use the redshirt recruiting tool, but you have to drop visits on the same cycle you use it. So all in one cycle you wanna do maybe 10 or more HV in addition to offering the redshirt. It leaves you exposed to rejection, even tho you dropped 10 visits. But the more effort you add with it, the greater your chances are that he will accept it