Growing cacti(of which the active component is Mescaline) is your best bet but it takes time and is a deep psychedelic experience which may not be your thing.
Poppy seed tea, Codeine? Some feel opioids are psychedelic. I've had heroin that made me hallucinate, but I'd taken acid a few days before.
Neither of these chemicals are legal to get high off of but are legal for other uses. Australia is pretty boring with our laws.