Like some others on here I still hybrid clean my round with a backpack for difficult or dangerous access stuff. The vast majority is trad and I get through about two hundred litres a month (only part time windie). At the moment I have a friend working in a unit that makes jet engine cleaner and somewhere in the process they produce pure. For the past couple of years I've been dropping empty barrels on his doorstep and they arrive on mine full. I'm sure if he minded he would say something but I feel I'm imposing and he won't even let me clean his windows in exchange. What I need to know is; what do I need to buy to make my own pure, what's the easiest/cheapest way to do it considering the small quantities I use? Who are the best retailers for what I need? Alternatively, the city I work in has a large cleaning company that sell pure for £3.60 for 100 litres.