Well, I live on the dry side of the state so even though we do get periods of rain it dries out in between. I have heard mixed reviews for straw but maybe people mean don't use it in the coop it's self because of books. I thought about maybe getting a bill and just throwing it in the run. P gravel is also an idea, but to add more rock to what already is basically rock just is too ironic. The mud dries up quickly compared to over on the west side but it still gets slick and icky. I guess I'll see what works and what mood I'm in when I get to the store as to whether I buy the straw or the pine shavings.
One of the biggest problems with wet straw is that it grows toxic mold inside the hollow stems. If you are using it in dry areas it can be fine but if it is going to get wet then you have to muck it out all the time. I raised baby calves on a dairy and we used straw in the covered calf pens but only until the calves weaned off bottles and buckets so they could go into a grow pen with powdered milk replacer (we only fed colostrum milk to get them started because once the cow was freshened her milk went back on the market for human consumption). We piled fresh straw in a pen for a few weeks and then cleaned the pen back down to the concrete to make it ready for a new calf. The amonia build-up in straw can be pretty bad so it really needs to be mucked constantly and not allowed to build up.