There are many discussions on using sand in coops and brooders at backyardchickens.com. Also, Gail Damerow suggests sand in her book, Hatching & Brooding Your Own Chicks:
Clean mortar sand or sandbox play sand makes excellent brooder bedding. It is not as absorbent as other types of bedding, but it absorbs heat more readily and evaporates moisture more rapidly and therefore stays drier. Perhaps for the same reason, sand is more resistant to microbes than other types of bedding, keeping baby birds healthier. Soiled sand doesn't stick to feet like other types of bedding can. When it is kicked into a drinker, sand doesn't float and discourage drinking but rather sinks to the bottom so the water remains clean. Provided it is sifted periodically to remove chick poops, sand lasts much longer than other types of bedding, making it extremely economical. [S]and is fireproof, but because it retains warmth better than any other bedding, you have to be more careful about heater placement to avoid overheated chicks.
At first the chicks ate a bit. This is ok because poultry need a hard substance in their crop to grind their food as they expand their diet. I bring them worms from the garden every now and then and hope to get the chicks outside later this week to explore their new pen. So the added grit is needed anyway.
It worked! The sand that did make its way to the waterer sank to the bottom and the waterer stayed clog free and clean overnight.