I really just want to comment on how pretty your Rottie is, but in an effort not to change the thread, have you thought about renting a pressure washer from Home Depot?
I used this company last year and they did a great job. Planning to use them again this year once the weather is a bit better. They do everything but I had them pressure wash and do all of my window, inside and out. Reasonable prices too.
EmmiJane, he thanks you for the complement! Its funny, if you ask 10 different people what breeds they think he is a mix of, you get 10 different answers. Our current favourite is a Beauceron mix (http://goo.gl/0YLQ) – far fetched, I know :)
TammiWS, thanks for the recommendation, I’ll be giving them a call today.