To clean a divided-light window, you need a squeegee that fits the panes. Weingard uses a hacksaw to cut one to size. He trims the metal channel ¼ inch narrower than the window pane, then files the cut edges smooth. With a utility knife, he cuts the rubber blade to the pane's full width and fits it into the channel so that it projects 1/8 inch at each end.
More in Upkeep
Chamois, and a lint-free rag or two
like a cloth diaper or old linen napkin
to custom cut squeegee for multipane windows