Green’s Dictionary of Slang

1. a hard task, which one performs only when coerced.

1856		G.J. Whyte-Melville Kate Coventry (1865) 111: I would rather give Brilliant a good ‘bucketing’ [...] than go bodkin in a chariot.
1914		C. Holme Lonely Plough (1931) 67: We’ll give him a bucketing some day over Ewrigg after rabbits.

2. (N.Z.) serious criticism.

2003

McGill Reed Dict. of N.Z. Sl. 36: bucket Harsh if not brutal criticism. Politicians give and take a bucketing.