Have you discovered Method dishwashing liquid?
On a recent cooking program mention was made of Method, a new, organic dishwashing liquid which contains twice the surfactant of others. This caught my attention as I have need of such a product for horticultural purposes. Available at Target and Walmart. Easily found among the other liquid soaps. The type with no added colors or frangrance is named 'Go Naked'! Not expensive.
This is an excellent product for its intended purpose. Remember, it has twice the surfactant so you only need a few drops. Last week I decided to try it out as a window washer. Filled an empty 24 oz. squirt bottle with water and added two drops of Method. Squirted it on a window, wiped with a newspaper and instantly had a shiny, clean window. No streaks! Yeah! I couldn't believe how easy that was. Quickly zipped through the rest of the windows with no effort. For the first time in my life I have truly clean windows and mirrors. Give it a try.