Works really great and dries really fast (acetone used as a thinner will do that for ya) Also, to apply many coats in a short amount of time, you can use baby oil between coats.
The "varnish" component of the nail polish will rise to the surface quicker and dry even faster! Don't forget to remove the oil before each coat, of course.
As for the cleaning of the airbrush, acetone, baby oil and finishing with acetone will do the trick.
Good luck!