Neverwet worked superbly at Wanee, keeping it from raining pretty much the entire fest! I did put an umbrella up the first couple days when the skies looked threatening and there was heavy rain potential. But I didn't worry not putting one up at all on Saturday when the day started iffy-grey but cleared up nicely. So not much of a rain test, but on brief headphone listening and listening in-car for the 6hr drive home yesterday, I heard no additional high frequency cut over the normal amount from the big foam screens.
I'll listen more closely at home over the next few days.. and also listen for wind-noise as it was quite gusty Friday and Saturday, significantly rocking most other mic stands around.
Besides the windscreens I also sprayed my hiking boots and a felt hat. Again, no real water test of note for these things, but the boots stayed much cleaner than they normally do. Having applied it about a week ago and undergone the rigors of a weekend festival, I may splash some water on all these things now that I'm back home to check how well it works at this point.
When I picked up the NeverWet outdoor fabric spray for the windscreens at Lowes, I also picked up the version intended for glass only. That stuff did a great job on the glass, headlights and front chrome of the car during the trip up and back. I encountered very, very, very, heavy rain on the drive up, basically driving directly through the "big purple blob" and really didn't even need to use the wipers. Also a few clouds of bugs. The bugs would still stick to the windscreen, but a few moments of wipers plus a few sprays of water from the windshield sprayer removed them mostly.
Once there, the parked car windows stayed clean and clear all weekend instead of becoming completely coated in yellow pollen from the live oak tree canopy under which we were camping. Seemed to work significantly better than Rain-X initially, but not yet sure how long the treatment will last before it needs reapplying.