The Wacky rig is used to add variety to the action of the worm. Rather than the straight “stick bait” fall of the lure, a wacky rigged worm tends to move at both ends so that the worm looks as though it is curling and straightening out as it falls. This slight change in action can be enough to trigger a strike.
To set it up, tie on an offset wide gap hook. Drive the hook straight through center of worm, just behind the back of the egg sac, and exit about two inches from the head. Make sure to submerge round part of the hook about 1/8 inch into the worm to keep it secure for multiple casts. You can use the weedless version of a hook if you are casting into heavy cover and concerned about snags.
If you need to get more depth or cast farther, you can use weighted hooks or ring weights, which fit around the body of the worm and are designed specifically for use with wacky rigs. If you’d like to give the worm a little different action, try using a small nail weight inserted into the center of the worm’s nose. This trick allows the worm to go deeper and will change the action on the fall.
Weight will also determine the rate of fall and the speed of the action. In other words the heavier the weight, the faster the worm will fall and the faster the action will be. A weightless wacky rigged worm will tend to fall slow and thus “wiggle” slow as well.