Iv seen my sulcata eat a couple small rocks in his enclosure but it was never an issue just twice he did it, even one time i seen my Sulcata eat some bird poop.
Tom's suggestion is a great way to go.
Very nice, yea i hate the small hair like thin spines that are covered and hidden on the cactus.
Sounds great, soon you need to buy your own spinless or with thorns and grow it!