I'm toying with idea of a headband but for the time being, I wipe my forefinger over my forehead and then lick the sweat off.
Saves me having to use my water supply.
ah, taking recycling to extremes - you one of these mad racers who just takes a single/smaller the better bottle?
(I refuse to call them bidons and whatever they are called I once refused water to a racer/fakenger who had very deliberately come out on one of my rides to save weight).
I think your approach is verging on dangerous - hydration is important.
And I would get a tech material headband.
drink and sweat away.