If you don't use fairy but squeegee off, or GG3/4 you don't leave a film of soap on the glass.
And the whole glass being made sterile, that doesn't make any sense. Sterile is that it has zero micro organisms on the glass. But if you would actually look at the glass under a microscope, all the microscopic valleys will have dirt and living microscopic bacteria and other stuff in them. As far as I know, you sterilize something will alcohol or other chemicals, killing all germs and bacteria and the like. Not by just pure water.
This sterile windows by pure water is really marketing bull, clean yes. Sterile no. They use distilled water in surgery yes, but that's not to sterilize tools etc, that is done by chemicals, ultra pure water is used, so nothing gets contaminated, no foreign substances are introduced to the sterile operation environment.
Sterility in medicine and surgery indicates a micro-environment (the surgical field) made free of infectious micro organisms.