Far more important then the short-term problem of repatriating your money, is: What are you going to do with it ?
The moment you talk about substantial amounts, all items you can buy with it, are "registered" and you will be asked, when the collated amount of registered assets is (significantly) higher then your official income would allow you.
Of course, you can have a more comfortable life, when your daily spendings on groceries/restaurants/etc can be higher. Though, that probably won't make you happier in life, nor will it "burn" significant amounts of money, without starting to waste money on unnecessary items. You can travel, in luxury, though, do you have the time for that and why repatriate the money, when you could spent that also from abroad stationed money ?
So, I think, first answer the more fundamental questions about the "what", before diving into the "how" challenge.
At the technical side, consider one of the crypto currencies, put it on the crypto account from abroad, laundry the money through one or more "independent" crypto accounts and let it land in your Aus bank account. Will still raise the questions, why you did not declare your wealth earlier, though -given the tax office does not have contrary evidence of statements like "earned through speculation"- will not give you penalties on wrong back-declarations. And it has become cleaned and legit. Depending on your local countries tax rules, you have to pay taxes on the capital gain (and probably on the base sum to). Though, now you can buy registered items with it.
Good luck, living in a controlled society, using unregistered money