Clark wrote to stop all unnecessary meds or supplements on the day of the cleanse. I add the walnut tincture (30 drops or 1 teaspoon) to the oil/grapefruit mix to kill parasites as they come out of the bile duct.

It is very important that you complete the parasite cleanse and then allow a couple or so days before you flush next. To actually kill the parasites takes a long time of exposure to the herbs. Some herbs such as Wormwood paralyse the parasites which then loosen there grip on whatever part of the body they are holding onto. Other herbs damage ,kill or force the parasites downward where they are excreted.

Adding black-walnut tincture to the flush potion may not actually kill parasites in a single small dose. Herbs used in this way are known as cholagogics and choleretics and their aim is to magnify the secretion of cholecystokinin and increase the flow of bile.