I wish I had discovered your post years ago. I have only been taking DE internally for a week, but I've collected a lot of information on it and I'd like to help anyone who will listen. My research started when I first read the words "diatomaceous earth" on a list of things it could be wise to stock up on. I found a local chain company that supplies tractors, I think, that carried Red Lake Earth Diatomaceous Earth and bought 3-20 lbs. bags. After a trip out of town I returned and ponied up. A Tbsp. mixed in water was like drinking mud. Day two I started the dogs on a cottage cheese/DE mixture that they inhale.
Long story short I passed a worm my second morning, but thought the taste just didn't match ALL of the reviews I had heard. So here's what you're reading this for.
Red Lake Earth DE is 67% DE and 33% Montmorillonite (calcium bentonite). There are some who say a calcium supplement aids the DE in it's health restorative properties, but the taste is a major turnoff and could keep kids, and fickle adults, from a regular cycle of use.
Perma Gaurd DE is 89-94% DE plus 28 trace minerals and reportedly has no taste, but a chalky aftertaste. Also, being 22-27% more DE sounds better at equal price points.
I will keep my clay DE for grain storage and back up, but I will be buying the purer DE tomorrow and expect better flavor if not better results.
Aside from knowing personally it is effective as a dewormer, I've read and believe other claimed benefits that include better hair, skin, nails, bones, joints, teeth, vision plus lower numbers that I'd like for myself and my loved ones like blood pressure/sugar, cholesterol, both good and bad. It makes sense on two levels for me. Firstly, parasites are known to rob nutrients from the host as well as emit toxins that effect physical and mental health. Secondly, people are DEficient. DE is mostly Silicon and that is a mineral that is NOT in most fertilizers or crops. I don't sell DE, but I want to. For me, this stuff is the Pharmaceutical industry's worst enemy.
So, while RLE-DE is food grade and effective, PG-DE should be flavorless in water and easier to get my loved ones to take regularly. If you have any questions, I'll try to hep.