I tried it - glued the fun foam to the rubber with rubber cement and then coated the other side with TIO&O to use them as unmounted.
The stamped images were great - but the TIO&O gripped the block better than the rubber cement gripped the stamp and when I tried to peel them off the blocks, the fun foam stayed and the rubber peeled away
So, while I agree that it works just fine for cushion, I'd recommend a different method of sticking it to the stamp