Rather than getting down on hands and kneew it mite be easier to sieve the sand to remove stones. This is also easier if the sand is totally dried out first, by spreading it out on a large tray and allowing water to evaporate.
i don't know whether torts can can eat them but i've read a lot of info saying sprouts are packed with nutrtrients, for us any how. i guess they might eat them in the wild (tortoise trust might know)