I was washing about 2x/yr up until 3 years ago, when other priorities sucked up my time. I need to get back on track. Single story with wraparound courtyard view, but all the windows have divided lites, so multiply the amount of squeegee work. The right tools and cleaner make the difference: pro-grade squeegee, good quality rubber with a sharp edge, a T-bar with scrubber sleeve, a pro-grade cleaning solution, deionized (DI) water for final rinse, and poles. Recently found a local window washing supply store, so I splurged on a 27” to 8’ CF telescopic pole. Besides window squeegee work, I can connect a brush or a microfiber cloth on a T-bar to dust ledges or knock down spiderwebs. The CF pole could be converted to a water fed system, but not ready for that yet. The DI water gets used to rinse cars and solar panels, squeegee rubber for indoor shower and mirrors. The older non-CF poles are used for the solar panels and for cleaning gutters.
The only problem with clean windows are the occasional bird strikes afterwards.