I used mixed C&S packet seed so I can't tell you which did better from there. I did have separate packets of mammilaria and lithops, both of these did way better than the mixed packet.

Lithops are very easy to sprout, just hard to keep alive!

I didn't use anything techincal. Just an old take-way plastic tub with holes in the bottom. I microwaved the soil for five minutes. Let it cool down. Soaked it through and let it drain. Then I just spinkled the seed on the top put the lid on and left it on a sunny windowsill.

Within a week the lithops were out. The others took a week or so longer. After a while I opened the lid a little to give them some air. I kept them shaded from strong sun by lying a tissue over the lid. They are still doing fine. The humidity is the key. And microwaving the soil keeps the environment sterile.

Here they are at three months old. They were repotted at around two months to give them a bit more room.

C&S mixed:

Lithops. You can see they are developing their true leaves now:

Swiss

I have never tried to grow cacti or succulents from seed but I am hankering to try.

Having said that I attended a lecture by an expert seeds man who essentially sells seeds now. But his lecture on growing from seed may be sumarized as follows get some bonsai soil mix. sprinkle your seed , then cover it with very fine gravel the sort you get from ann auqarium supplier and lightly cover it.
he prefered to water from the bottom ie placing pot or tray in water until it comes up close to the surface and then let it drain away.But the bit I found interesting was the fine gravel, sitting on top as it does it dries out quickly this frevents mould or fungi growing which he said was the greatest threat to new seedlings .

Now as to heat, he didnt talk about that much but he suggested using a small fan that you can find in an old computer to blow a breeze accros the surface. Now I dont know whether you would need a transformer for this , but some one might know.

I dont know whether it is as cold in Broken hill as it is in Bacchus Marsh but I suspect you get your moments. Have you considered a heating pad. Yhese are available from hydroponic out lets.. presumably they have a temperature control allowing you to heat from below and experiment with heat. I have heard that heat applied from the bottom is best for raising seedlings.

This is what philofriend said in part on the Us forum:
"I never found it necessary to use a heating pad with cactus seeds, especially this time of year[ie spring] when it's warm outdoors. Guess it depends on what you're sprouting though. The extra warmth can speed up germination. At the times I've used a heating pad, I put a towel over the pad, set a 10-gallon aquarium over that, set the pots in the aquarium covered in plastic wrap (checked daily so they weren't too wet or too dry), and kept the pad set on low until I saw the seeds had sprouted. You don't have to use an aquarium, that's just what I had readily available. But, this time of year, I starts things outdoors, let the natural heat and humidity do the work for me. If you use a heating pad, be careful so you don't catch things on fire."

As to what you can do with your hundreds of dragon fruit, I know what you can do with one hardy and mobile seedling. I promise I won't tell any one.

Baldric