The viscosity of pure antifreeze will present a problem. You'll still get better than air cooling, but it won't be ideal. Distilled water doesn't stay non-electrolytic for long, and as the metals dissolve into the water, it will start to conduct, and create a galvanic cell if there are dissimilar metals used in the system. The rate at which this corrosion occurs depends on the potential of the dissimilar metals (gold and silver won't be as much of a problem as aluminum and copper). To avoid conducting electricity (both galvanic and in the event of catastrophe) some people use mineral oil or alcohol to get around this problem. There are advantages and disadvantages to using these alternate cooling fluids. Mineral oil runs into the same viscosity problems that ethylene glycol does. Also-alcohol, like mineral oil, does not have as advantageous a specific heat as water. The highest performance cooling will come from distilled water combined with a wetting agent like soap or "water wetter". However, that doesn't prevent the galvanic corrosion or conductivity problems. IMHO, some form of alcohol is the best compromise, but YMMV.
3C2X1(<b><i>Genius</i></b>).
Even though I'm a stranger, at least my average post is intelligent!