I too have a Volcano, but haven't experienced your problem. All I've ever been told by AP is that the hornback straps are not intended to be exposed to water, which I take to mean that one should not apply a fluid cleaning product to the strap as well as avoid direct immersion of the strap in water.
However, I would ask to piggyback upon your posting by asking whether anyone has any insights on a way to clean the underside of the Safari strap, which tends to discolor with wear, perspiration, etc.