I don’t know about pipe-cleaners, but this is what I use...
Light anti-vibration
Medium anti-vibration
Heavy anti-vibration
NAD C-series top and bottom-side anti-vibration (to look like NAD Master-series pucks).
A collection of 3D models, also showing one with neodymium magnet embedded.
I 3D-print these and (as can be seen) combine with other vibration-reducing materials (golf practice balls, squash balls, rubber slip-resist pads, magnets, etc.) to suit each application.