I think I am too late to help you.
Herbal medicine is allowed to bring in Australia, as long as they are in sealed bag and there's no bug in it. Of course you need to declare it. Just this monday I returned to Aus through Sydney airport, I declared I have plant matters with me. The custom asked me what it was, I told them it's tea leaves and herbal medicine. They just scan my baggage and let me get through.
Please note that nowadays all bagages are either scan or hand check. There's no green passage to pass thru without checking.