water. lay it flat to dry overnight, then wash it with a mild detergent in the sink. finish with a final rinse to get all the remaining stubborn sand right out.
fact: sand sharks, also known as sand tigers, are the only shark known to come to the surface of the water and take a gulp of air. on the top of the speaker, barely caught them in the picture. i also have the stand that the speaker rests on. if asking price is met, i will ship stand for free. i am getting out of theater and back to 2-channel. 