I came across a one pound refill box of Renz E-Z window cleaning detergent concentrate at a yard sale. It says you can clean windows through the screen at the rate of 15 windows in 15 minutes.
It sat on the shelf in the garage for several months until after I power washed my house. I thought well what a good time to look into this product. Since I did not have one of their sprayers, I mixed up a 40-1 solution after making the concentrate by adding 2/3 cup of the powder to a quart of water. I put it in a garden sprayer and dosed the windows up with it and rinsed them with the pressure washer.
The results, although not good enough for my customer’s houses, was very impressive. The windows dried mostly spot free with just city tap water. If I had one of their sprayers I think it puts the soap on at a much more concentrated level with lots of suds. I would expect that they might have dried perfectly spot free with a much greater concentration of soap.
I have ordered one of their sprayers and will redo my windows with it to see if they truly will dry spot free with a tap water rinse.
I did a search on the forum for renz e-z and nothing showed up. So, if anyone has tried this, I would like to know how it worked for you.