And yet is the most widely used, and oldest salt on the market.
I can dig up those same posts about RC, TM, RS, and just about any other salt on the market. Do not blame a salt on the poor husbandry practices, or lack of knowledge of hobbyist.
If you actually read any of those threads, it was mostly some other issue, that the OP thought was the salt, but later on in the thread it was debunked.
Again, if IO is such crap as you have said, explain to me why nearly every public aquarium(who cares about the life of their livestock more so then a hobbyist), and research facility uses it?
OOh wait, you can't. You'll just post more google hits about IO being crap without actually reading the thread.
And still waiting on the evidence you said you have(your words exactly "I have sent it out to a lab") on the brown crud being clay.