Hi Pete,
I use a similar sized pole an awful lot, I would never attempt upstairs windows with this method though.
But on technique:
Again, the pole is really only of any use on fairly large window panes.
If you are going to use a pole, get the Unger squeegee handle that you can rotate and have the channel at almost any angle you want, for pole work, an absolute must!
Wash window with applicator, do not wash right to the top of the window, else you will leave an edge that will have to be wiped with your dry scrim lest you get runs.
Same applies to the edges of the window pane, try not to wash right up to the edges.
Fit squeegee on pole, rotate channel to an appropriate angle for the height of window-the higher the window, the more acute the angle you will need-
1. wipe squeegee rubber with damp scrim.
2. Hold squeegee on glass with top edge of channel against the edge of the window pane and also at least as low on the pane as the squeegee is long.
3. Slide squeegee to top corner and draw across as vertical as you can to the other side of the pane, finishing completely vertical against the other edge.
Unless you have picked up bits of paintwork you should not need to wipe the squeegee rubber again.
4. Continue as from stage '2' making sure you overlap. once you have got it to the point that you can squeegee off the window without the pole simply continue as normal.
An extention pole used on domestic accounts will rarely be of any real use, you will never be able to do a decent job of upstairs windows using a pole on domestics, it will take you far longer to do a window and it will never be as good as it would be if you were up a ladder.
On downstairs windows you will gain nothing time wise over using your pointer.
I am an extremely accomlished window cleaner and have used a pole for a great many years.
If you are using it on shops or certain types of commercial premises then it is a must, but will only be of occasional use on domestic accounts.
But as they only cost a few quid (relative) it is always a good thing to have one for when it will be of use.
Best of luck!
Ian