Aww how nice of your Dh! I hate to tell you this but my Dh has zero issue. I am sure the peppermint helps but mostly he has zero gag reflex and that allows him to down almost anything. Right before he drinks it he says for my baby girl and throws it back!
Has your DH mixed it with anything like juice? Did you already mention that? I can't recall.
Really hoping the stuff works, how great would that be if it were as simple as swallowing some gross liquid!