Ronnie I wasn't having a pop at you mate, but if you are leaving spots then something is wrong somewere! I'm not slap happy at all, the videos that I posted are not that clear, but they are regualar monthly cleans that I have been doing for 4 years, and if you watch carefully I am very methodical, each window gets a couple of horizontal strokes at the top of the pane, followed by 2 good strokes up and down each section of glass,,I follow this up with a rinse down the length of the pane with the brush held just off the glass, on a regular monthly clean then generally I find that there is just a little bit of dust on them and maybe a few cobwebs on the frame, and so that is all thats needed to get them spotless, If they need more scrubbing due to bird muck ect, then thats what they get!
I have an excellent reputation with my customers, and believe me I'm not happy with anything less than perfect results.