Joe, I was a huge proponent of Cool Tool II for several years. I think in the coarse grits (like you said) it makes a HUGE difference.
With more fiddling/time, I've come to where I start with 320 or 400X, and I think Cool Tool II is a bit heavy for those grits. I use Cool Mist in a spray bottle.
I also use Windex at the very fine grits. I have stuck to the real stuff too... I bought some "store brand" crap at wal-mart, and it actually etched the steel while I was sanding with 1200X. Talk about a great way to piss me off!
I think I'm just going to sand-blast everything from now on