I use straw in my dog run. One bale covered it for almost a year and it's easy to clean up after them. They don't track in any mud or dust , which I do get in the house because I have pea gravel in another area of the yard.
Misty- Samoyed Mix, Tannor- Golden Retriever CGC
Robyn- GSD CGC, TC, Midnite-GSD CGC,TC, Brennan-Golden Retriever CGC, Batman-Husky/Greyhound , Apollo-GSD