Green’s Dictionary of Slang

p.o.(q.)! excl.

[piss off! excl. + SE quick/quickly]

(Aus.) go away!

[Aus]W.H. Downing Digger Dialects 39: p.o.q. — go away!
[Aus](con. WWI) A.G. Pretty Gloss. Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: p.o.q. Piss off quickly, go immediately.
[Aus]D. Stivens Jimmy Brockett 109: You P.O.Q., brother, and let somebody handle this job who can do something.
[Aus]S. Gore Holy Smoke 10: And you’ll have the toe of my boot behind you, if you don’t p.o.q. orf outa this.
[Aus]N. Keesing Lily on the Dustbin 129: It is suggested to dopes that they are not worth their salt [...] so ‘pull your socks up, PDQ’ (pretty damn quick) or ‘POQ’ (piss off quick).
[NZ]McGill Reed Dict. of N.Z. Sl. 162: POQ Piss Off Quick, before you get a BSA, a Bloody Sore Arse. ANZ.