I asked this last year, trying to get legs clean of cakes in mud and manure for the online sales. Best advice was to soak them. I filled up a shallow water trough with soapy water and stood them in it for about 20 minutes and then started gently scrubbing. It took forever, but I managed to save most of the leg wool. Thankfully we finally bought a tractor this last spring, which has allowed us to keep the pens much cleaner, even with all this rain.
