Cinnamon or Mint flavored oral gel, relaxing the gag reflex "just enough". He'll enjoy the tingle, you'll enjoy the flavor and never worry about gagging again. Pea-size amount to start and increase as needed. Most get instant "results". Specify flavor when ordering. Not sure? Try the sampler pack.
NOTE* Only the cinnamon and mint relax the gag reflex, the rest are for flavor only. The two are included in the sampler pack as well. Enjoy!