It might raise you pH, but if you're okay with that and your tank inhabitants are all suited for it, should be fine. Just boil it first for a good long time and a do few water changes to the boiling water to remove toxins, then do a running rinse in a tipped bucket stirring the crud out and letting it rinse out as the bucket fills. You'll find this more manageable in small batches rather than doing a full bucket all at once.
Make sure it's legal to take the sand before you do it.