Yes a vibratory polisher will work but rocks use a grit process verses brass polishing using a metal bb or ceramic pellets. I buy Grit at one of those chain type tool stores its as cheap as I can find it. The bigger the tumbler the more grit it will take, its a Four Step process of grits start to finish and your average barrel tumbler uses only a cup or less depending on amount of rock. After the finishing polish some folks still run an ivory soap and plastic airsoft pellets for cushioning to clean them off and give a high sheen.