Boots gor-tex and polish

[stevierst]

Leder gris isn't that waterproof in itself tbh. I use my altbergs every day rain, hail, or shine, polish them most days and the leather still gets wet in a downpour.
I've been using altberg/gore-tex boots for years using all sorts of different polish over tens of thousands of miles. It really makes no odds what you use, as long as you polish them with something to keep the leather supple.
As has been said before, it's the drop liner that keeps the water out, not the leather.