The idea that this can work (WFP dry windows) is ludricous. Remember that petrol engine that gave 150mpg, the battery that lasts forever and weighs nothing?
It took hundreds of years of science and observation to get osmosis, and then millions of US space race dollars to get reverse osmosis.It took twenty or so years of the best auto engineers in the world to come up with the wiper blade after internal combustion engines powered vehicles.(invented 'brilliantly' about ten years later by a window cleaner for window cleaning).
If it really finished dry you wouldn't need pure, if you don't need pure you don't need half the science.
Such a thing is possible but when it happens the following conditions will probably be met.
1. Someone makes a breakthrough in a field totally unrelated to window cleaning. For example Dyson has blowers that can produce unheard of pressures (vacuum cleaners suck they've turned it around).
2.Some brilliant individual push's the barriers
3.Several people /corporations all come up with the same idea at the same time.IE. liebnitz and Newton both invented calculus at the same time, and there are countless other examples.
4. Such a breakthrough wouldn't be held over for a trade show and it wouldn't be a window cleaning magazine scoop, it would be on News at Ten and in Scientific Amercian.