I've had fantastic luck with it.
It kills everything however, it will actually sterilize sewer water.
I don't think it survives the small intestine, generally is broken down and gone before it reaches the colon.
I take an Enteric coated Oil of Oregano because I want it to kill off everything in the small intestine, but not the colon. And then just take a Pro-Biotic to give me some new friendlies.
To clear out the colon I had to squirt some Ionic silver up there, not fun, but it works. And again, repopulate with probiotics.