Damp wiping pads (according to the instructions) and this original schnapps give me absolutely no streaks.

I have the same problem and will try to solve it by pre-cleaning the windows with a damp cloth. I am of the opinion that the window surface is simply too dry without damp pre-cleaning and that is why the streaks appear. Can you please try this and then give us some feedback? Thank you very much.

I was given the tip - but haven't tried it yet - that using a mixture of distilled or demineralised water and a dash of window cleaner as a cleaning agent won't leave streaks.