This is how I handled this same problem....wet, muddy areas.....I put an ad on Craigs list explaining that I wanted just some old hay for my chicken coops and their runs. I had two persons reply. The one I was interested in has hay bales that have been sitting for months and are dusty and dirty. They'll be perfect for the chicken yards and coops. I keep cleaner hay or shavings for the nests, though. The woman is charging me $2/bale. When the weather's dry, I also add grass clippings, leaves, fireplace ashes....they love to roll around in the ashes and peck through the leaves and grass clippings.