Honestly, I haven't had more than 1 hiccup at a time in decades.
I learned back then that hiccups are an involuntary spasm of the diaphragm. Make them voluntary and they stop immediately.
The way to do this through NLP (or whatever), is to whisper in a person's ear that you'll pay them $20 to hiccup when you snap your fingers and then snap your fingers in front of their face right after. They'll try to force it. That's all it takes. Hiccups cured.
Once you learn to do this, you'll be hiccup free for life.