Green’s Dictionary of Slang

crack n.6

[? euph. crap n.1 (4)]

(S.Afr.) nonsense, rubbish.

[SA]A. La Guma Threefold Cord 24: ‘You talking crack,’ Charlie told him. ‘God, man, she’s not your blerry wife.’ [Ibid.] 94: ‘He got records, too. Bings [Crosby] and others.’ ‘Blerry white crack.’.