Dekay the "cloth" that you're remembering is called "crocus cloth" which is available at good hardware stores, but not just any generic home improvement shop. It's an extremely fine abrasive which I use to burnish my AC cords' plug prongs to a shiny state (just prior to applying Kontact). I also use it for burnishing edison fuses & AC power cable ends when doing installation work. This is really great stuff, but unfortunately it seems that many people are unaware of it.
Regarding those sorbothane "tube spacers" that you want to try out, could your also use a thin sheet of Teflon, cut & pin-punched to fit. Either material would insulate those high voltages; one might possibly sound better than the other (or not)?
Regarding those sorbothane "tube spacers" that you want to try out, could your also use a thin sheet of Teflon, cut & pin-punched to fit. Either material would insulate those high voltages; one might possibly sound better than the other (or not)?