I am brand new to this, but several posts suggest parasites can be eliminated when the DE is swallowed and abrades their outer skin/shell. Apparently is an old remedy for insects, is non toxic and is often used in livestock where it is mixed with their feed to eliminate parasites. So far, I've not seen any results, but I just started Thursday night. Do a search on Diatomaceous earth here and you'll find a lot more information and testimonials.
By the way- I have been dealing with a known Tapeworm problem for a couple of years. I passed an 18" intact worm a couple of years ago and a number of segments since then. My health is going downhill and I will do almost anything to safely get rid of this problem.