BTW, I do it by basically following the scare technique.
I do whatever I can to try and trick my body into believing I was just scared. The whole take your breath away due to fear thing. It jumps the body and tends to do the trick.
But half of the trick is immediately following up that with focusing on breathing. Doing what you can to forget that you just had the hiccups, and focusing on not having them by taking slow, steady breaths with rhythm.
But for scaring yourself, it's easy. Quickly turn your head, focus your eyes on something really quick that was originally out of your sight, and acting like you were just really surprised by what you just saw. Act like what you just laid your eyes upon was horribly disturbing or scary. Natural reaction is to kind of drop your breath, your whole body tenses and "jumps", and you really focus. The point being you focus, basically losing focus on your hiccups (which everyone, when having persistent hiccups, focuses on said hiccups because they are so damned annoying), and turning focus onto something else.
This "scare" tactic helps because it preps you to shift into something else. Immediately after the "scare" you should change your breathing, continue to forget about the hiccups and move on. It usually works right away, and if it does not, do it again. And again if necessary. After a few times, it should always work. If it is not, it is because you are moving back to focusing on the hiccups every time. I'm guilty of this even when I've perfected the trick I basically invented for myself. It's just so hard to cease focusing on the hiccups when you want to forget about them. It's almost like telling someone to ignore the bright light without closing your eyes when the bright light is the only thing you can see wherever you look.
