Digital rectal massage (see references below) has apparently been reported in the literature to help stop hiccups, mainly by disrupting the vagal afferent limb of the hiccup reflex arc. Name says it all. Essentially, you stick a finger up the bungholio and massage the area firmly until the hiccups stop.
It apparently stops hiccups fairly quickly.
Termination of intractable hiccups with digital rectal massage. J Intern Med. 1990 Feb;227(2):145-6.
Termination of intractable hiccups with digital rectal massage. Ann Emerg Med. 1988 Aug;17(8):872.