In reply to UKC Gear:
I've used Icebreaker Merino wool T shirts 150 to 260 and long Johns years and just washed them with normal TESCO or similar Non-Bio detergent. Works a treat and some of the 260 I have had for quite a few years and loads of washing. The Icebreaker Everyday range isn't anything like as good but don't have experience in washing other brands of merino wool clothes.