Mark you are doing Exactly what I did not want to do, and this is were the few months before-hand came in handy, by explaining there could be problems with the first 2/3 cleans, all my customers seem to understand, but to be quite honest most don't care, just as long as they get there windows cleaned, but I felt I had to fore warn them and then follow up with the letter.
Another thing I did not want to do, and that was to do just the tops, if I was going wfp then it was all or nothing, I am more lucky than some guy's, in such, I can return home and refill if I run out without to much loss in time.
Your comments on the windows was interesting, and I spent a little time on the downstairs windows just watching what the water does, the thing I noticed after washing the frames and the windows, then returning to do just windows, was the dirty water left on the frame face, and if this is left it dries dirty and spotty, and this water can run down onto the windows, I now give the frames that little extra rinse and have had no problems so far.
were the glass is concerned, I have only ever noticed sheeting and beading, like has been mentioned so many times before. but I will continue to take the time to see what happens on the glass.