I use gulp minnows as my anti-skunk bait at the lake I fish at. I normally use Sufix Elite as my line of choice with no leader. I usually rig the 4 inch minnow with a 1/4 ounce jig head. I've caught walleye, hybrids, bass, sand bass, channel cats and largemouth bass. I even fish the 2 1/2 inch model under a bobber for bluegill and crappie and it works well.
As ways to improve i usually fish it with a slow retrieve at first and vary it if I get no bites. You never said how you normally rig yours.