Other than water?

I have a koolance water cooled case that I'm going to refill w/ coolant as soon as I get the chance. Is it possible to run a watercool set up on rubbing alcohol or anything other than distilled water+antifreeze?

Yes, but your best results will be found with distilled water + an ainti corosive or biocide addative.

Strait alcohol can cause problems with acrylic glues, and other types of plastics.