Buckmark, alot of us are using the hollow body jigs and injecting them with Crappie Nibbles using the Bait Pump. I seems to be working real well.
Check out this link. Randy,aka Slab Hunter has a link at the bottom of his post if you are interested in the pump.
http://www.crappie.com/gr8vb3/showthread.php?t=28970