Can you link me to the "instruction sheet" in question? I have the Tech Inspection Form, and that's as much technical detail as I have as to what is required. It sounds like I'm supposed to have something more. If there's an instruction sheet out there, now would be a good time to get it.
As far as arguing about and/or justifying what is used on other tracks; I'm really not interested in a debate, but I can tell you that I've never been required to run pure water...ever, so that's what prompted the surprise. No, I don't run pure
antifreeze for obvious reasons; I run water and an additive that is not nearly as lubricious on the tires in failure mode.
If you're allowing water wetter (which is full of lubricant), I'm fine...just as long as running this event doesn't mean replacing my water pump. The instructions say the seals will promptly fry if run without a lube present in the coolant.