Hi Steve,
You are best placing this in the window cleaning section.
There are lots of guys that do WFP.
But best advice I can give you, althou it wont beat being with a pro for a day.
Its fairly easy, makes sure the water is pure and the tds is 0.00 and no more than 0.01
after brushing make sure you rinse well, that the technique its in the rinse off. Avoud vents where possible. As the dirt is a pain.
Dave