A shindig, a shebang, and a shillelagh are all from Irish expressions.
Shindig comes from the fighting Irishman’s habit of digging the steel toe of his boot into his opponent’s shins.
Shebang is from shebeen, an Irish reference to an illegal bootlegger.
His wooden club took its name from the famous oak trees near the Irish town of Shillelagh, so yes, he could go to a shindig and wipe out the whole shebang with his shillelagh.
