my wool is always wet and dirty from hunting in the rain. I just wash it in the sink by hand then hang it on the line to dry.
Water wont shrink it the dryer does (so im told). but been doing it this way for years and wash lots of wool from filson, kom, Columbia, woolrich, and some others. Never hand a problem.
My mom recommended that I lay them flat to dry and put a couple weights on the corners to keep from shrinking, but I only did that once and never had any problems just hanging it on the line.