Caco, try and identify where the gagging is coming from. Some of mine was from the mucous draining but mostly it was from swelling from the radiation damage. If there is swelling he is going to need and ant-inflammatory like Decadron to get that under control. It has done wonders for me as I come through the peak damage psot rads. I can swallow pretty good and the gagging has become minimal. I still have mucous, but that's easing off as well. Make sure you ask if he feels tight in the throat and watch his breathing.