I wouldn't think anybody would be selling an antifreeze/coolant with no corrosion protection at all. I'm not by any means an expert, but here's the way I understand things at the moment:
Plain ol' pure water is the Ideal Coolant from a heat transfer perspective. Trouble with that is that freezing and boiling points are too high and too low, respectively.
Ethylene glycol mixed with water takes care of the freezing/boiling problems quite nicely. E.G. doesn't transfer heat as well as water, but a 50/50 mix works just fine in that regard, particularly since road car cooling systems are normally built to be pretty robust.
With the exception of the "safe" coolants like Sierra (which use less-toxic propylene glycol),
all coolants that I'm aware of (standard green, DexCool, Nissan, Toyota Red, Honda Green, G-05, etc.) use ethylene glycol. It seems to be a common misconception that "non-green" coolants don't use E.G.: they do.
Corrosion inhibition is the next major issue that must be addressed. E.G. does nothing to stop or slow down the corrosion that is almost certain to occur when water is left in contact with aluminum and/or steel/iron for two years.
Silicates and phosphates are pretty effective corrosion inhibitors: It's my understanding that this is the only reason they're added to coolants to begin with. Some makers, though, have determined that side effects of these things would be nice to avoid. (For example, the Japanese makers seem unanimous in their feeling that silicates prove unduly hard on water pump seals.)
OK, great. But they can't simply remove silicates & phosphates from their formulations without replacing them with some other corrosion inhibitor.
DexCool, I believe (going from memory) uses something called Organic Acid Technology (OAT) as its corrosion inhibitor. As we've read about, there are some issues with that specific formulation.
Some other coolants now are using what they call Hybrid OAT (HOAT), which is...better. Somehow. I guess. I really know very little about this. Peak Global Extended Life has some "proprietary corrosion inhibitor" - who knows what it is.
The whole game appears to be finding a suitable replacement for silicates and phosphates as corrosion inhibitors. An added benefit seems to be longer life: silicates get "used up", while these HOAT-type chemistries do not - at least, not in quite the same manner.
I wrote this out mostly hoping that whatever misconceptions I may be laboring under might be corrected.
But, I think the short answer to the question of corrosion inhibitors is, "Yes, you could formulate a coolant without them. But for street use, I don't think you'd want to."
