I wouldn't have thought it would make a lot of difference to be honest, just rinse and scrub any horizontal part of the frame top and middle UPVC sections, I clean and rinse the frames and glass all round then I go round again and clean just the glass on first cleans, I haven't had a complaint yet, sure some just don't like the idea of WFP but they are a real minority i.e. 3 in 4 years for me and they got dumped