Reverb

Has anyone had any experience creating reverb inside a build? Just read a article about this man in Arkansas who spent the last 30 odd years building guitars from scratch with no experience at all. Some one x-rayed one of his builds and on the inside he had an old saw blade and a couple of springs to create reverb, and it got me thinking. So I did some research and found a couple of cbgs with creating reverb using springs inside the sound box. Any thoughts ?