three legged bowl

Hello Everyone, I would like to make a slab built bowl (draped over a mold) with texture on the inside and I'd like to put three legs on it. I would be shaping the legs or feet from a slab wrapped around the short end of a wooden spout maker so they will be hollow. My question is do you have to poke a hole in the legs for the air to escape in the firing? Thanks to anyone who answers, Sandi