To be fair, perhaps you could show everyone one or two non-DHA properties that you think can double in 5 years then.
The risk-free low hanging fruit in Australian property is mostly gone, taken by those who got in early. A good deal of what remains is potentially rotten and overpriced, relative to long term inflated-adjusted projections. Property that yields the most is often (but not always) overpriced. Beware inordinately high yields, just as you should be wary of ultra low yields.
I borrowed massively to invest in bayside Melbourne three years ago. Nothing has doubled, although a few have come close to doubling. Rising rents mean that some of these houses are close to paying for themselves. Still hanging in there.
Personally, I remain bullish on the cheaper seaside Melbourne suburbs like Seaford and Frankston & (non beachside) North Frankston. But on the very strict proviso that one should not over-pay and, furthermore, one should stick to dual occ sites -the sort of place, increasingly rare elsewhere in Australia, where one can retain the existing building and construct another at the back. There's no sense in listening to the self-interested promises of local agents who will harp on about these suburbs being the cheapest beachside suburbs in Australia (well, that much is true). Fly or drive there and do your own due diligence over a few weeks - meet the local bogans and ask them questions like "so when do you plan to move elsewhere, now that this suburb is being gentrified."
Other than the above (and don't forget the proviso), I have no risk-free offerings to share with you. A few country towns with growing populations have good prospects that are not entirely risk free. Keep away from one-horse mining towns (no matter how high the yield) - these are notoriously cyclical.
The problem with many country towns is that the banks are pretty tough when one wants to borrow to invest in the bush. I guess they've been burnt before. And if they do lend you money, they sometimes have a habit of asking for it back when there's a downturn in the bush. Happened to me, I didn't like it. So I've stuck to the cities ever since.
May the Universe be with you. Remember, if in doubt, keep your money under your bed or in your (big four) banks.