If i were u, i'll never wipe the treated surface with anything as abrasion can damage the sharp peaks of the coating. On my rear windscreen, i just blow off any remaining droplets of water or just dab it with an MF cloth. Same as our Astro satellite dishes...no washing and no wiping. The grey surface is treated and highly delicate.
On any coated cars (paint coating) with the exception of OptiCoat, i like to blow the water off and dab the remaining droplets.