When I first started this program of Doc's I didn't have any of Barefoot's dewormer. I think the Clarks stuff DID work, but we here in America do have the privilege of having the best herbalist around when we have Barefoot and his products.
So, if I couldn't get Barefoot's dewormer, I would go with the next best thing that I thought would work--Clark's in this case. I would want to kill the parasites and get healthy even if I had to compromise a little to get there.
Hope this helps you.