Used the window cleaning two cloth package and could not believe how clean and streak free the windows were when finished. I will say, the windows were not filthy dirty to begin with, but this product performed better than any I have ever used. I just kept the wash cloth damp in order to maintain a dry finish cloth. I also rinsed the wash cloth frequently under warm water. After about 20 windows the finish cloth was still pretty dry. Can't wait to do it again next year! Only kidding. Still wish the windows were self cleaning, but if you have to clean them, this is the product to use.