Green’s Dictionary of Slang

(Aus./N.Z.) to caress the buttocks; to ‘goose’, i.e to stick a thumb or finger into someone’s anus.

1976		D. Ireland Glass Canoe (1982) 13: Just as he reached the vinegar stroke, Mick dated him.
1985		R.G. Barrett You Wouldn’t Be Dead for Quids (1989) 145: Norton [...] dated the snooty receptionist on the door; she screamed.