Honestly, get a window cleaner. He even brings his own water, like ours isn't good enough (de-ionized apparently to avoid streaks).
When we first moved in a pigeon apparently the size of a pterodactyl defecated down the bedroom window and I rushed to the shops to get my very own extendable pole (every boy needs one). Attached it to the tap, engaged the water flow. Basically ice cold water ran straight down my arms, under my clothes and into my pants. Bracing.