This thread brought me back to the days when my wife handed over our son and asked me to "fart" the baby. I accidently came upon a procedure that worked on both of my sons when they had gas as infants. I beacame quite a show for the family to see!
I would sit on a chair with my legs together and put my son on his back on top of my thighs with his legs facing me. I would hold his legs and roll them towards his chest, almost like he was doing a reverse ab crunch. Just as his butt would raise, out came the gas! I'd wait a few minutes and repeated the routine until empty.
Sounds funny but give it a try, it may work for you too.