Sary, I totally understand the skepticism. My friend just put on facebook that she is doing the OP thing with coconut oil, and put up a link about how it can seriously help teeth.
As someone who doesn't trust dentists (and you wouldn't either if you knew what I've gone through with them. Saying I need fillings then having pay for a job well done, just to find that they either did it WRONG, or they didn't bother to reinforce the filling and the filling agent came out a couple days later leaving a lovely hole in my tooth that is way bigger than what I went in with, then telling me that I have to pay for their mistakes...just...no thank you, I'll take care of my teeth on my own until I find a competent dentist that actually does the work correctly) it's difficult for me to keep my teeth and gums in top notch condition. Brushing, flossing, and peroxide wash seem to be making my mouth extra sensitive (and there's still a bad taste at the back of my tongue no matter how hard I brush it, or gargle mouth wash).
That said, I looked at the links you posted, and took a look at some other things as well. I see that scientists have done "tests" with subjects, but they don't appear to have any idea why someone shouldn't OP, only that it somehow worked. Even if you google "How does OP remove toxins" or something to that effect, you just get more success stories, How To's, or someone trying to debunk it.
I'm sorry, but I don't have an answer. It looks like a lot of the pages I've seen trying to debunk it add a couple sentences to the bottom of the page saying something like "But since there's no proof that it harms you, there's no harm in trying OP other than the cost of the oil". It's a natural remedy to a problem a lot of people have.
I might try it just because I'm trying to reduce the amount of chemicals I use in my daily life, from trying to lighten my hair naturally just to dye it with a henna dye because the chemicals in normal hair dye hurt my scalp, and I'm not happy with my brown hair (except I haven't seen any results so far on trying to get my hair to lighten naturally).
Maybe you can put your own study. :) You could experiment with different oils, and monitor what happens over a 30 day period of OP versus your normal routine and see if you can tell a difference. I might do this as well. I already use coconut oil and seaweed wraps on my legs since I have dry skin, and olive oil, sugar, and cinnamon as a home-made body scrub.
Sometimes
Science just takes the easy route of making a theory, and it looks like the ones who "researched" this did just that. "Does OP really help teeth?" "have kids from a third world country who've never brushed their teeth OP, versus kids who've never brushed their teeth start without OP" "the kids who OP had quicker and better results" "OP must be good for your teeth". Sure they answered their question, but the only people who gained a benefit were those kids. There's no data behind the experiment.
I hope someone here has the answer for you :)