Are there scientifically proven ways to get rid of hiccups?

Many of the remedies for mild hiccups may work by creating a stimulus that interrupts the signals causing the reflex. In effect, you take the nervous system out of its rut. So, for example, when you drink from the wrong side of the glass, you may be exciting nerves in the back of the mouth, nose, and throat that aren't stimulated by normal drinking. 
Breathing into a paper bag works a different way. It increases the carbon dioxide (CO2) level in your blood, and it's been shown that as CO2 levels go up, hiccups tend to recede.
Another maneuver: You exhale and then take a very deep breath and hold it for 10 seconds. Then, without exhaling, you breathe in again, pause, and then breathe in a third time. 
The most commonly prescribed medicine for hiccups is chlorpromazine.