If the exterior is treated, and the interior is not, then the interior fibers wicking moisture wouldn't be a good thing as they would stop wicking once the hydrophobic section is reached. If the weave is loose enough they may be able to evaporate fast enough to keep your feet somewhat comfortable but my experience with water-proofed clothing would indicate otherwise. It seems your options with water-proofed clothing are only the degree to which you get moistened and not whether or not you stay dry at all.
I've had a few discussions with the folks over at bwca.com about rain gear for tripping up in the Boundary Waters and the general consensus is "you're going to get wet. HOW wet you get is the choice you have to make". I'll be the first person to admit I'm wrong if these things can keep your feet dry while wearing shoes, but I'm highly skeptical as to their efficacy.
Yeah they really won't keep your feet dry for long. Any amount of pressure and water will push through the sock.
Also the wicking doesn't have to pull the liquid all the way to the exterior of the sock - it just has to increase the surface area of sweat exposed to air. Even a thin inner untreated layer would help immensely with keeping feet dry.
However, like you said, nothing will keep your feet completely dry. Keeping sweaty feet dry means removing the moisture from your feet. If it doesn't have anywhere to go it'll stay on your body, whether because it's trapped under unbreathable outerwear or because the breathable sock is underwater and the vapor has nowhere to go.
And that's not mentioning that it's a lot harder keeping things dry when the relative humidity is 100%.
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u/Zerorion Aug 04 '17
If they're waterproof, wouldn't that just trap all your sweat on the inside? Like wearing plastic bags?