Green’s Dictionary of Slang

a blackthorn club or bludgeon, seen as a typically irish weapon.

1827		Pierce Egan’s Life in London 22 Apr. 933/1: [T]he O’Callaghans with tooth-picks in their mauleys like the branches of Old Irish Oak Trees; the O’Shaughnessy’s likewise with dusters of China in their bunches of Fives as, big as door posts; and the O'Grady's also with bits of Shilalees! [...] in their fists thick enough to floor a Mad Bull.
1846		United Service Mag. 551: A mighty big bludegon of blackthorn [...] was an heirloom which had been in his family for several generations [...] looked upon as one fo the household gods, and orignally termed ‘the China dustier of Mount Bog’.
1849		Mirror Mthly Mag. 97: He was known throughout the barony as ‘Jerry the ounshagh’ (half-witted fool); whenever he made an excursion he was armed with an ‘illigant bit of black thorn, a nate weapon,’ which he termed his ‘china-duster’.
1865		J.H. Amherst Ireland as It Is 18: Faith, but here's a nate fly - duster -- wouldn't I like to dust the coat of ould Stone wid this same.