Budgie smugglers is so old even my mum had heard it used in the 1960s. Dunny was specifically a stand alone can based outhouse so of course most people don't use it unless they still have them. Rural areas still use more traditional slang than metro areas because well.........they are all a little slow out there.
This article gets dragged out every few years out here *yawn* about the rise of spamspeak and the decline of strine.
Strewth mate! Chuck another prawn on the barby, and crack open a tinny from the esky, I'm as dry as a dead dingo's donger. Deadset!