When I left school at 15 I went to work in the fashion dept at the Co-op, I know, glamour at it's best and 19s 11d a week! Anyway.. One of my jobs, as a junior, was to clean the mirrors in the changing rooms every day. Neat Meths on then newspaper to polish. I hate the smell to this day!
The original Vanish liquid used to be fantastic for streak-free window cleaning - until Reckitt Benckiser bought the company over and decided to add all sorts of different cr@p to what had been a purely natural product. I looked for an alternative and found 'Squeegee Off' at B&Q, and I'm totally impressed with it. Seems B&Q now sell it under their own label, but I'm unaware as to what they call it. Have a look on Google for it at the best price. I'm not involved in promoting it, it's just that I have this thing about my windows being clean and streak-free.