In reply to Phil4000:
Hi Phil, not to sure which article you are referring too, but multi-day apline routes may push you down this route so your outer socks and boot liners do not get wet if your biving.if your on a day route or the option of a tent for the night is on then maybe not required as you can dry your boot liners and socks out over night in your sleeping bag.
My own experience is of the later.
HTH Davey