Narrow Gaps - What would you do?

I just quoted a job that has a fake balcony where the railing comes out a couple inches from the door. It’s narrow enough I can’t fit my arm in past my wrist, so a couple inches clearance.

I’m sure I can design and make a low profile squeegee to be able to clean it, but is there already something out there that will handle this?

I also have a WFP and just had the thought of using a spray bottle and a scrub brush. Wet the window with Dawn water, use my T-bar on a pole to scrub and then rinse with RODI water from my WFP?

Good morning, I know this post is old but I am in a similar situation and wanted to ask if you ever figured out the easiest way to get all the glass clean? Thank you in advance

I used a Moerman squeegee on a 3 ft pole. It took a long time and was hard to detail. If I were to do it again, I’d use a flatmop type tool with windex.