Before you are about to hiccup, draw and hold a deep breath, then drink a whole glass of water steadily.
The water should be a comfortable drinking temperature with no ice.
You have to be drinking when your body sends the signal for a hiccup. Don't chug your water too quickly, but don't leave time between drinks for a hiccup to slip in.
Pour enough water and take a deep enough breath. You must keep drinking water without stopping or taking a breath until you have passed the moment when you would have expected the next hiccup. It's better to drink longer to be sure, because once you have a stomach full of water, it's hard to try again with another glass.
We haven't suffered from endless hiccups ever since we discovered this method. If you agree that this is the best way to cure hiccups, please let us know at hiccups@oursmiths.com.