Visco-elastic materials for vibration damping is not weird science, snake oil or voodoo which is peculiar to audio, it's a wildly studied field -- there's a lot of scientific and industrial literature on the subject -- that has resulted in the development of a range of different substances and products to do the job across all kinds of different applications. (There are also different kind of shock absorbing or damping technologies, including pneumatic solution, in use across industries -- like electron microscopy -- that have been adapted for audio use.) How application of any of these impact sound is going to vary -- damping or wholly eliminating the injection of structure borne vibrations into a record player system is important to lowering spurious signal and tracking distortion, since, as I mentioned, a record player works by converting mechanical movement into electrical signal. And how effective any solution is will depend on the particular problem and how well suited the particular solution is to the problem at hand. And, of course, the audible impact will depend on the nature of any structure borne vibration that may or may not be present in the first place, as well as the effectiveness of the damping/decoupling solution at the frequencies and in the direction where there is vibration. Other damping/decoupling solutions that might impact sound might work by lessening transmission of vibrations from an audio component to room surfaces (like decoupling a subwoofer from the floor to lessen room rattle).