Not a teacher, nor a member of an elite group.
lingokid: My generation (the 1970s) used it a lot even because American music was the most aired in Oz and always has been.
probus: So if you say that in Australia "toys in the attic" means "bats in the belfry", I believe you.
I'm aware of the title's occurrence in a couple of films, a play, and elsewhere, but as to its usage in general speech, like the OP I can only speak from my own experience. I have lived in Australia for most of the last forty years. In the early days I was very involved in rock'n'roll as a music and a business, so I lived in that environment. Apart from the occasional reference to the Aerosmith album, I have never heard the phrase "toys in the attic" used in general conversation, in Australia or anywhere else.