It's not rubber glue, it's rubber cement, and like FastEddy says, it's available in any office supply or Walmart or art supply. You brush it on both mating surfaces, let it dry, then press them together. It comes off when you need to change it. It's the same procedure used to bond a sanding disc to a disc sander. Silicone will work, but it will be a real hassle to clean off when you need to change the slipper.