It is pretty much
quackery.
There was
a good debate on this subject awhile back. (As well as
another.)
The subject comes up from time to time, and the studies show that the product does actually work NUTRITIONALLY ... but does
zippo for internal worms.
This whole "rough edges of the DE" is only correct when the product is DRY ... and flies out the window once the product is ingested (and thereby moistened).
It is quackery to use it for internal parasites ... and most people don't know how to differentiate between "opinions," claims, and "advertisements" (which can say anything) ... and
published scientific studies (which are held to a standard).
Ads and people "claim it works"; the
published science says
it doesn't.
Jack