Sand is cheap , and if at least 1 FOOT above grade, cuts down on parasites as it dries so fast. If your runs aren't level, you will have to shovel it up the hill occasionally though.I use liriope ( Monkey grass ) to hold the sand on my runs, as they are on a hill. The Orps don't seem to like the stuff, and it really makes a mat that holds the sand.Masonary sande is the best, as it is coarse.
A nice by product of using sand is that if you screen it every day, you have instant fertilizer. Chicken litter mixed with sand, NOT shavings, does not burn my flowers , or bushes. It's a win-win.
Holy cow, I didn't even THINK about monkey grass... I'm so dense

I've got the stuff growing only feet away from my incredibly muddy run and I'm just wishing and praying and thinking about what I could possibly grow that wouldn't be destroyed by the ladies. DUH!
They've never messed with it before... just not palatable I guess. Thank you! That and a good load of sand oughta make a difference.