Yes, there are a lot of claims about DE that are patently false. It is not a "cure all" by any stretch, and its effect on worms is virtually nil.

What it does do is, when DRY, it can kill mites/fleas, etc. ... but (again) its entire effectiveness as a parasiticide lies in it being DRY ... which is kinda negated when ingested and moistened

Studies have shown the mineral element in DE *is* beneficial to health and growth, with marked weight gains in livestock, but its effectiveness as a wormer is dubious at best. Actually, there has been an ongoing 12-year study on DE as an internal dewormer, that should have ended in fall of 2012, so the results of this (the largest) test ever done on DE ought to put the truth/falsity of these claims to bed once and for all.

I don't have the time right now, but if anyone wants to click on the link above, find the study, and post the results that would be great.

Jack