This forum amazes me, When I first came on here about 12 months ago and was looking at advice etc, Every post I read said DO NOT CLEAN TOP FRAMES/VENTS apart from first cleans (and even then stay away from vents!). Now most people are saying, 'clean top frame every time'. There does not seem to be any consistancy in what way is best to use wfp to clean a window.
You get consistency from me Chopsie
I've never done top frames (I have my reasons). However, to be 100% successful with this method you need specific equipment, knowledge & learn the technique correctly.
I've had it sussed for years (through necessity) & you can fly through work including first cleans with perfect results!
Remember, sheep follow sheep.