Washing windows on the outside is a big job. But, I found and easy solution over 30 years ago that works! It has made this chore a lot simpler. Secret weapon, "Woolite"! What you need; a bucket of water, a soft brush on a long pole, a bottle of *Woolite (*I use original or concentrate) and a hose.
Step one: Pour a cap full of *Woolite in a bucket of water
Step two: Hose off the window with water
Step three: Using the soft brush, dip in bucket and gently wash window
Step four: Hose off the window with water, again
Step five: You're DONE! Let air dry, for a spot free finish!!!
The *Woolite works great on bugs and gunk. The soap causes a sheeting action, so after rinsing with water, there is no need for drying or using a squeegee.