I am guessing its like flax?
We moved our dust allergic pony from straw to flax last winter - and can't get our heads around why we didn't do it sooner
You either use rubber matting and then put down a small layer to really stop the pee from splasing back when they pee (can't really put it anyother way!)
or - like we do - put down a massive bed (we use 6 - 8 bales) and every day take out the poo - and make fair the bed
Every 2 - 3 months we then dig out the entire bed - awful job! I won't deny that - its a real ewwwwwwwwww job and discinfect out the whole stable and relay the whole bed
in the summer we use bout 3 bales as he's hardly ever in so its a small bed
the wee moves to the bottom and makes a firm but comfy bottom layer - the top stays dry
no smell - at all
no damp or wet
we have had no mud fever problems (we were told by a few that we'd get mud fever as straw dries off the mud and wet and the flax wouldn't?)
his chest is mega improved
mucking out is easier and quicker
I wish I had a picture of our summer bed to show you - its been down just over 3 months now - its coming up this weekend - and it looks like its fresh and new - and smells of - well nothing! Obviously if you dig down to the bottom layer that's not so good! But it compacts down and for most horses stays nice and comfy
hope that helps a bit xxx