In free stalls with Dairy cows, we used sand with lime used several times of year. This allowed great drainage of urine and also prevented a lot of the problems of mastitis by not allowing the liquids from reinfecting another cow, not allowing bacteria to grow and the lime kept it bacteria free.
Of course with the cows we buried rimless tires to help prevent them from digging out the stalls and giving them a bit of spring action.
As for eating the sand, the girls ate out of a microchipped grain feeder and also a cement feed bunk. Don't know how that would work with goats, but it helped our girls a lot.
Good luck!