@Iluviaporos - Another episode they had was a woman who had severe hiccoughs and it turned out that she had damaged some part of her lungs and she ended up passing away. So, severe hiccoughs which you can't get rid of are not always the harmless kind of myoclonus.
I haven't had hiccoughs in a long time, at least not badly. I figured out how to stop them from happening. If you really pay attention to what part of your body is tightening every time you hiccough, you can relax it in the same way you can relax a cramped muscle.
Once you get into the habit of it, they don't even seem to happen all that much anymore, although I noticed I occasionally get them after I go jogging.