In my past, I have found that 'forgetting to hiccup' is the best cure, which is why so many take to drinking water upside-down, a spoon full of honey/sugar/salt, holding one's breathe, standing on your head, and so many others I have failed to name. In grade school, I had a teacher who if you hiccuped in her class would have you stand before the class and publically demonstrate your 'disease'. The results were obviously effective in 'scaring' them out of you.
A medical student once announced that it was a chemical imbalance in the stomach that causes them.
'I' still hold that they are most easily dismissed by the mind as unneccessary (forgotten) or irrelivant (scared out of you because another concern is more relivant).
*The world record for the longest hiccups used to be like 5 years!