Pasture Plants That Poison
Gene Logsdon, The Contrary Farmer

...an old remedy for internal parasites in livestock is to soak black walnut hulls in their drinking water. If you think that sounds far-fetched, a much publicized control for internal parasites in humans is black walnut tincture, made from soaking particles of black walnut hull in vodka. Think I’m kidding, don’t you. Google it.