I was planning on buying an investment vibrator because I really can’
afford a vacuum investor.
If you’ve got an old (or new for that matter) orbital sander; mount it
upside down, attach a small board (12x12" or less) to the platen.
Criss-cross the board with a couple of rubber bands, cut from an inner
tube or use the stuff the lab techs use when drawing blood, to hold the
bowl. How’s that for a home brew shaker (makes an industrial size martini
too).
Dave