Good money in it Chris and you know your going to get alsorts of answers.
My own method is with the pressure washer and lance, I fill the detergent bottle up and stick the pressure washer on low pressure, give the guttering,soffits etc a good soak and then turn the washer upto full power and blast it off, if there are any stubborn bits I stick my brush into a bucket of say TFR and just give the area a good brushing.
Jobs normaly done in half the time than off the ladder.