What do I think? I think you're thinking is sound. No matter what level of short-term goodness comes from taking supplements isolated from foods, no one really knows the long-term effects. If your body doesn't need them or want them, at the very least they stress our organs of elimination (and our organs always have something better to be doing than eliminating excesses of things we willingly put into our mouths! lol)
Are the toxins you're trying to rid yourself of, toxins that could be gotten rid of through cleansing and other/various non-supplemental protocols? If so, I always choose the cleansing/non-supplemental route.
'Sorry I don't have more to offer about IP6, but I definitely have not researched it well enough to advise someone much more than general thinking.