well, when you got back out of the car, had the fluid in the resevior gone down all the way? Cause if it didn't, then just put more fluid in the res. before starting the car, and don't let the level drop below the bottom of the res.
As for corrosiveness, i think your idea about degreaser and water should work fine (not real eco-friendly, but hey, when have cars ever been?), and the rest will cook off the next time you drive the car.
Take a deep breath first. You should be ok
Later
Jed
