Start of reply - 5.30am
I regularly use an extention pole, the one being an Unger 5ft pole that extends out bout 9ft or so.
Slap on the applicator and wash glass, do not wet to the edges.
2 techniques for using the squeegee on the pole;
The first being to slide the squeegee up to one of the corners, and try to squeegee as normally as possible, turning is difficult and the higher you are working the less you can squeegee with each pass, but you can normally work it down until you can reach without the use of the extention pole.
The method I prefer is to use a squeegee handle that allows you to rotate the blade to any angle you like.
Mine is the Unger swivel handle, but I think all the major makes do their own versions.
So the glass has been washed as before with the applicator, squeegee is on the pole and is swivelled around until the channel is nearly upright, providing there is room to do so I start the blade low enough on the window so that the squeegee can travel up the full length of the actual blade and then simple sraw the squeegee all the way along the window pane and finish flush against the other side.
Depending on how long the channel is, you usually only need to make a couple of passes until you are down to the point where you can reach comfortably and squeegee as normal.
If you have done it right you will not need to tidy up afterwards with any detailing.
I only use this on big windows, even those with separate panes above the main big one, with those you need to be sure your applicator isn't too wet, and you usually cannot slide the blade up the glass, so you simply start flush to the window frame and draw across.
Or of course you simply start at the top and draw down.
You can usually start flush to the top and slide the channel along the top so that it is only on the final time you put the squeegee onto the glass that you are left with that wet line on the glass that you need to wrap a scrim around your pole to tidy up with a little detailing.
But the more you practice with squeegeeing with an extention pole, the more adept you get at it.
Most of my work is done with WFP now of course, but prior to WFP I used this technique constantly as much of my work is on shop fronts and so on.
I never attempted upstairs windows with an extention pole, I found that quality was way too compromised to be able to do so.
Ian