Joe Offer wrote: “Whalin’ up the Lachlan.” — In the old days there was an army of “sundowners” or professional loafers who walked from station to station, ostensibly to look for work, but without any idea of accepting it. These nomads often followed up and down certain rivers, and would camp for days and fish for cod in the bends of the river. Hence whaling up the Lachlan.

Which starts us off-topic, but it leads to a complex of "Lachlan" songs, e.g. "Four Little Johnny Cakes"/"Camping in the Bend," also from Old Bush Songs:
Hurrah for the Lachlan,
Come join me in my cheer,
For that's the place to make a cheque
At the end of every year."
The singer was "camping in the bend" and fishing... and occasionally "borrowing" from the people who actually do work.

We also find sundowners in "The Wallaby Track," which is also about those who wander but don't really work. The term is attested as early as 1869.

"Flash" is a British term, but the Australians really seem to have adopted it: Charles R. Thatcher wrote "The Flash Colonial Barman," plus Old Bush Songs has "The Flash Stockman," and there is also a song of "The Flash Sydney Shearers." There was also a broadside, "A New Flash Song, Made on the Noted George Barrington."

And I'm clearly getting into one of my information-spouting moods, so I will stop before I become even more boring than I have already been!