Firstly, I'm not in Oz, so take that as a disclaimer from the outset!
Citric acid is a culinary ingredient that can often be found in middle eastern type grocers, and it may or may not be available in domestic supply stores as a descaling agent. It was quite hard to find in the UK for a time, apparently to discourage the heroin addicts
Ethyl acetate
may be available from specialist plumbing suppliers as a pipe welding solvent for PS waste pipes, where it gets dubbed as "MEK substitute" (in N America, at least). A similar solvent to look out for is butyl acetate, which appears to work for its own version of CIELO (therefore, "CIBLO") but the crystallisation step with the citric acid may well require some refinements, since the solubility of both water and citric in the BA is lower than in EA. Anyhow, butyl acetate may get sold as a general-purpose cleaning solvent but as I say, I know nothing of the Australian retail market and understand you may have something of a nanny state problem at least as bad as the EU!