Honestly people have “stayed wet“ for centuries without chemicals. We’ve hung our clothes to dry instead of using machines too.
Lots of apparel products are highly overrated. And those water resistant coatings just come off anyway.
I think the best thing to do is go on a hike near a river with a dog, and watch how the dog marches through the water unwaveringly even when it’s cold!
Unless you really saturate cotton in wax/oil so it has no breath-ability, it only holds up against showers. It becomes sodden and little use in persistent rain. PU coated polyester rainwear can perform on a different level in persistent rain. I've not found natural materials which perform as well, although some expensive tweeds are reportedly exceptionally good.
Lots of apparel products are highly overrated. And those water resistant coatings just come off anyway.
I think the best thing to do is go on a hike near a river with a dog, and watch how the dog marches through the water unwaveringly even when it’s cold!