You can't do much in Australia, so I wouldn't be surprised if you can't but Potassium Nitrate. You can try chemists or even online stores.
me: *walks into chemist* worker: hello how may i help you me: i want potassium nitrate please worker: .... worker: wait here please. worker: *calls cops* suspected terrorist in my shop :| Victoria there are so many cool things you can do with it, i am going to make a massive rocket for fun
I cri ery tim Potassium Nitrate - 500g https://www.amazon.co.uk/dp/B002X6HHOG/ref=cm_sw_r_awd_Dd3MvbFBQ4H2T Unfortunately your Amazon doesn't sell it. I'll just fly over to you. Not suspicious at all...