Black Walnut tincture is one of the most proven and used tinctures. It kills over 100 types of parasites. Black walnut is also a very effective cancer fighter and there are many reports of tumors shrinking and disappearing altogether with its use. Black walnut is also a powerful source of potassium. Black Walnut tincture is one of the most proven and popular Crooked House Herbals solutions. It kills over 100 types of parasites. Black walnut is also a very effective cancer fighter and there are many reports of tumors shrinking and disappearing altogether with its use. Black walnut is also a powerful source of potassium.