I just fill a condom with hair gel, tie that up, put two small bouncy balls in the remaining space, tie that up, put that into another condom to ensure non-leakage, then put that inside a knee high or thin sock, and tie that. V'oila! Packer.
It passes the feel test too. I frequent a gay bar alot, and asked a few of my gay male friends to tell me if it passed the grab test...and they were like...holy ->-bleeped-<- son...that feels real.