I found the trick to clean the windows is to not drag the cloth too much. You get small swipe, turn the rag, swipe again then rinse the rag and repeat in another area. Its a big hassle to clean windows but if you clean too much window before rinsing the rag your just pushing the VG around rather than picking it up so it smears...looks clean but hazes right away again. I finish with windex and a gazillion paper towels. I just use Mr Clean, tried many other products but its not the product that doesn't work but how its applied to the window. Just spritzing windex or whatever doesn't work very well, its a 2 step process to cut the VG off the window so it doesn't rehaze the next day again on you.
We hazed our vehicle windshield the first summer we vaped so bad that the window didn't defog at all once winter came but a tiny spot on the bottom then went to the dealer thinking the heater core failed to later research its a con of the VG.
I came to the same conclusion as you about how to do it.
Paper towels are worthless. I grabbed up some microfiber cloths from work and had pretty good luck with them. Just spray on some Windex and wipe. As long as I turn it regularly and don't use the same area twice I can do the whole windscreen with one cloth.
Never quite figured it out. I have a suspicion that Windex doesn't actually dissolve or cut the VG. So like you said you can just end up smearing it around, then the Windex evaporates and leaves the VG on the glass. Someone said that Dish works better. Maybe it actually dissolves the VG, it's pretty good at cleaning tanks. I never got around to trying it though.
A lot of mornings lately I have to drive with all the air on the windscreen and let my feet freeze. It doesn't take much VG to fog up your windscreen when it's really cold outside.