sounds like a waste of money and time to me.so let me get this right.
youll clean the windows at say 50ft,bring the pole down,attach a camera,haul it back up to the window to check whether its clean?if theres still a bit of dirt on you ll bring it down again,haul it back up and clean again?
at that height i wouldnt bother.just scrub and rinse as best you can.