Green’s Dictionary of Slang

(NZ prison) dismissive phr., used to negate the supposed effect of a problem experienced in prison.

1999

D. Looser ‘Boob Jargon’ in NZEJ 13 33: no effect int. Expression meaning: ‘I’m okay, not a problem’ - shows that the bad news, punishment, hard work etc. that the inmate has to face literally has no effect - they are not troubled by hassles of prison life.