as you get higher, you don't have to lift off the glass to rinse, rest the edge of the brush on the window frame and tilt it so that the bristles are off the glass and rinse away
The window frame and brush head will take a lot of the weight this way.
On a normal house it is a piece of cake to hold off the glass to rinse, only tougher as you get higher.
And YOU WILL get used to using the poles, just give it time
Ian