If someone says they have the hiccups, ask them to prove it. 9/10 times, their hiccups will disappear. Having to summon a hiccup in order to demonstrate will trick your diaphragm into just Not Hiccuping.
I've been able to twist it around on myself with some success as well, but it takes practice. You realize you have hiccups, then /try/ to hiccup. Actively try to make yourself do another one. It'll stop.