I know it must work, because I've seen using sand to bury the carrots in recommended so many times, but I've never had success with it at all; my carrots always sprouted a bunch of little white roots, to the point of being pretty much a solid mass of little white roots. That said, though -- I don't have an actual basement, my choices are pretty much the garage (which gets too cold in the winter) and the crawl space (which I think is way too moist).
One important point, no matter how they are stored, is that the tops must be cut off; they suck the life out of the carrots in short order.
