Yes, you can definitely use the bellicon with bare feet or socks with rubber grips.
Do not use regular socks as you may slide off. You can also use shoes, however it is a great workout for the muscles in your feet if you go barefoot. If you normally wear inserts in your shoes for everyday walking, you may want to use them while bouncing as well.
Currently, we are not carrying any socks for the bellicon, but you can see more of our accessories here.