Why not just try it and see? Place a sheet on top of a component. Place a sheet inside. I would think a phono stage would be good but why not try the rest? Then if you want to try transformers, cut a piece to fit around one. Leave the backing on, hold in place with Scotch tape or rubber bands, only remove the backing and use the adhesive once you are sure you like it. Even then might want to test a bit to see how removable it is.
Same process I have used with other stuff. Test small, build up to large.