I use Sweet PDZ. I do like it, it absorbs moisture very well, and does seem to help with odor. In the spring I had moisture issues I think I discussed further back in this thread. I cleaned their shelter as soon as there was moisture getting up into the shavings and then spread a thick layer of Sweet PDZ. It took a lot of it and was a very expensive endeavor, but at at least it helped keep down moisture and ammonia until it dried out for the summer.
For your question, I don't know that it will work as a soil amendment. It does absorb large amounts of moisture, but I would think for mud situations you would need a truck load. I would spread it on the mud in their shelter and it would absorb a lot of moisture, but I would still need to shovel it out and replace it with each cleaning. That was also a situation where I think the angle of the hill the shelter is on was allowing surficial ground water to come out about a foot into their shelter, kind of like a seep. After a couple of weeks, there was no water left up hill and the issue was resolved, at least until next spring.
If you can get Sweet PDZ locally, you may want to buy a few bags and choose a small test area to dump it in. It is about $16 a bag here (well, in Rock Springs where I get it 100 miles away) and if nothing else, it is great to throw into bedding to absorb urine.
I have never noticed it getting into their hair or wool, which I imagine some people would be concerned about. When it is dry and they walk through it, it gets coated on their hooves (dust-like, not caked-on-mud-like) and keeps them dry. I imagine in places with moisture related hoof problems it would benefit that as well.
Hope that helps,
Gregg