Ask Lemmy

Yeah, apparently something along those lines has been shown to work:

Drinking through a straw with the ears plugged is a folk remedy that can be successful.[34] In 2021, a scientific tool with a similar basis was tested on 249 hiccups subjects; the results were published in the Journal of the American Medical Association (JAMA).[35][34] This device is named FISST (Forced Inspiratory Suction and Swallow Tool) and branded as "HiccAway". This study supports the use of FISST as an option to stop transient hiccups, with more than 90% of participants reporting better results than home remedies. A non-commercial resource describing a similar suction-based technique using a regular straw and water bottle has also been published online.[36] HiccAway stops hiccups by forceful suction that is being generated by diaphragm contraction (phrenic nerve activity), followed by swallowing the water, which requires epiglottis closure.[37]

https://en.wikipedia.org/wiki/Hiccup#Folk_remedies the "non-commercial resource" referenced: https://hicfix.com/

Another approach that worked for me once:

A breathing exercise called supra-supramaximal inspiration (SSMI) has been shown to stop persistent hiccups. It combines the three principles of hypercapnia, diaphragm immobilization, and positive airway pressure. First, the subject must exhale completely, then take a deep breath. Then, they must hold their breath for ten seconds. After ten seconds, they must take another small breath without exhaling, then hold their breath for five seconds. Again, without exhaling, they must take another small breath and hold their breath for five seconds. Upon exhaling, the hiccups should be gone.[33]

https://en.wikipedia.org/wiki/Hiccup#Folk_remedies