Any elongated blunt instrument used to beat common sense into one's uninformed counterpart. At times, a schwackum stick can be a doppleganger for a golf club, baseball bat, tree limb, shillelagh, or sawed-off pool cue.
One day, while driving down the road one bright, country day we see a cow in the middle of the road. We honked, it didn't move. So we reached in the back for what we call our schwackum sticks and we schwacked that cow back to the field where it belonged.