Family members breeds horses and cattle and you should see the coats shine and solid cattle using a mixture of garlic etc for worming.
The only problme is it has to be given about 3-5days before each full moon. So only the prize Horses and the cattle ready for sale in the next 3-4 months get feed that de-wormer.
So placebo, I do really doubt that :-)
Gawler techniques do wokr, one of teh relies had a good dose of abnormal cell growth and used it in conjunction with conventional treatsments. remission 8 years now.