Windows can be a real pain in the butt. Just when you think you have seen all the gunk the light changes and reveals 15mins more of work.

Windex sprayed on a paper towel works pretty well for interior windows that have heavy crud on them (like RainX interior anti-fog) After cleaning your interior windows well once, wiping with a clean/dry (top quality as Ytown said) paper towel seems to be the best way for interior windows. Exterior windows seem to do best with spraying the windex on, lots of paper towel agitation, and multiple buffings of a dry paper towel. Here in Atl lately it is so humid that the Windex sometimes does not want to evaporate... For deep cleaning of the windows try Bon Ami or a specialized windshield cleaner at any auto-specialty store.

One other item of note. When on a trip to the ocean recently hosing + windex + buffing did not remove all the salt spray on the windows but a spritz of the OEM washer fluid did quite easily. Perhaps the best window cleaner is closer than we might think. I'll admit I have not tried dipping or spraying the washer fluid on the window and agitating with a paper towel. But with the bugs and humidity here a test is just a walk to the garage away.

Will let you know how that goes...Lee