as a knitter- some wool is treated to be superwash and will hold up to washer/dryer without shrinkage/felting, some is not... I think this explains the responses in this post as well.. personally I handknit wool socks and machine wash them but air dry them.. but I do that with a lot of things and thus have a rod and drying rack in the laundry room.

If we're onto recommendations, I bought a pile of 50% Merino technical Tees from Mountain Warehouse's outlet store for $15 each a couple days ago, Ive had a few others I've been using at work for the past month. Great for such activities plus quick dry even without a dryer.

I always put my superwash wool socks in the dryer. I find that they grow on my feet and a trip through the washer/dryer brings them back to their original size.

Hmm I have always washed all my wool stuff including my Icebreaker base layers and Tilley Un-Holey socks both 100% Merino IINM in cold water and dried on high along with everything else. If they shrunk it's hard for me to tell as the arms were never long enough to accommodate my wingspan. No appreciable difference. I think after the first or second time what has come out will come out and you can more or less stretch it back to size. Been my experience anyway. I'd rather have bone dry clothes from the dryer personally.