I have a load of diapers in the washer, with the delicious anticipation of hanging them outside in the sun. It is only supposed to get up to 69F here today, but in Utah, that is nice and warm for late March. Cloth diapers are not difficult to clean, but nothing breaks down winter gray and detergent residue like UV rays. In August it will be so hot that my prefolds will be bone-white in twenty minutes, but I'll take what I can get.
I also washed two loads of wool covers and longies in my washing machine. Yes, in the machine! I am the first person to tell you that hand washing wool with a hand-made bar of yummy scented lanolinzed soap is one of life's great pleasures. Elizabeth Zimmerman said that one should view hand-washing a sweater in the same task category as bathing a baby. I agree wholeheartedly.
That being said, I have four children and a husband who need my attention, a business to grow, and other day-to-day tasks that never go away. So, sometimes I find myself with a big pile of wool that could use a bath, and me with other things to do.
I am a huge fan of peace fleece wool yarn. The story explains the name, and it does my heart good to support such an earnest effort. Beyond that, peace fleece knitted longies and soakers are practically indestructible, which is important for busy babies and toddlers. I have tried single-ply merino and while it is beautiful and soft as butter when first knitted, the pills quickly take over. Shaving wool is also cathartic, but after a while, I start thinking about other things I need to do. Single ply wool also felts if you look at it cross-eyed. I do think it is the perfect wool for a newborn though.
Peace Fleece doesn't pill at all. Some complain that it can be a little scratchy. It can be, until it has been washed a few times. Then the mohair blooms, the wool softens, and it makes a tough but soft fabric. Most of their colors are heathered/speckled with lends the wool a great depth and beauty. This close-up of my daughter's grassroots longies show how these pants literally go with everything. 
After attempting to felt some baby moccasins and a purse out of it, I realized it was even tougher than I thought. It took ten wash cycles and several goes through the hot dryer to get them where I wanted them. I heard stories of others washing their peace fleece in the washing machine and one day, with a pile of dirty wool, I decided to try it.
My wash routine: warm water, delicate cycle, lots of room for everything to circulate. I pour some Eucalan wool wash in, turn everything inside out and throw it in. I should note here that lanozied wool is so water resistant that I have to personally hand-dunk and saturate the wool or it would just float on top of the water during the entire wash cycle. Really!
I like to live on the edge, so I have also washed Noro Kureyon, Little Turtle Knits farm yarn, Irish Baby Knits riddermark and lindon merino, Blue-Faced Leister, Cascade 220 and organic Jacob in the washing machine, with no ill-effects!
Today I was out of Eucalan so as the washer filled, I took one of my wool wash bars, and sudsed it in my hands and melted it in the water. Presto!
The important thing is to not obsess. Like so many things in life, there is no one exact perfect way to wash your wool (or your diapers)! You have your own routines for washing your other clothes, right? It works the same for cloth-diapering. Try one way, tweak it to fit your desires/water/preferences. I find my routines evolve as I go. It's not rocket science. It's just laundry, right?
If other people in your household do laundry, make sure you don't leave your finished load unattended. I would not recommend you put your hand-knitted wool in the dryer. Hung over a clothesline does the trick perfectly.
