I do believe the herbs kill parasites though. I also feel Bile plays a part, but I dont agree that the herbs have no properties in themselves. Some things- such as garlic that kills parasites, also is used by some Countries as a natural pesticide.
I also had dropped some Black-Walnut capsules under my desk by accident this Summer- and noticed a dead cockroach laying belly- up near the capsules.
You can ask about the value of herbs at the Barefoot Herbalist forum.-- MH makes his own tinctures and dewormer.