Eucalan Wool Wash - hands down.
The wool is MUCH softer after being washed in Eucalan than anything else I have tried. The difference is considerable. My preferred method is to soak/hand wash in the sink, wring out and dry (without rinsing) though I sometimes get lazy and use the machine, still trying to avoid the rinse.
I tried the Kookaburra Wash product but it's not in the same league. I cannot see a difference between it and my standard wash,
Charlie's Soap.
Every sock I own is wool and most of my shirts.