I've used it as a gasket between the subs/speaker and the mounting surface. I have used it on little trim panels that like to rattle in the doors. It probably has more uses but 7 out of the 10 things it could do i think non hardening modeling clay does better. I would agree that it is still useful but in a narrow focus. Not really a deadener, can't really use it as a decoupling layer, but it might be necessary to have it lying around just in case.