As a big fan of Ajax, try this:
take a squirt of Ajax and soak the towel in water and clean your windows real good then rinse away the hard water spots, dirt and contaminants.. then apply some rain-x. like new again. crystal clear and protected.
only problem with rain x is this. if you have it applied already and you for some reason need use your window washer. the washer fluid mixed with the rain x can make it hard to see on rainy days.
so the key is not to apply a lot of rain x, a little goes a long way. try applying it with a sponge and NEVER use a paper towel to apply it. way too much dust particles in the paper towels and will not spread evenly over the window forcing you to use too much.
Um, Ajax will not break up hard water deposits...
Ajax is a dish soap and at best it removes some waxes and grease as a prep wash for polishing or LSP application... Using ajax without applying an LSP will be a direct culprit in the appearance of waterspots on not just the glass, but the entire vehicle!
If anything, you have had success by...
. As all of your detailing photos have been, in the dark. Completely useless as for as any detailer is concerned.
as seen here...
. Removed by the friction of the cotton towel, but only when the "waterspots" were unmentionably mild, AND on top of a layer of previously applied rain-x. Just a ring of dirt on top of polymer glass protectant.
Ajax WILL NOT remove waterspots from bare, untreated glass with a towel, let alone any tool you apply it with. It's chemically impossible for the ajax to break down the mineral deposits.
...Let alone severely aged spots on old glass, good god.
What you are saying here is destructive, that is not advice.