Hey there,
Unfortunately there are no "Official" AU Clean sweeps being ran at the moment. There's only an EU one at the moment. With that said, that doesn't mean one of the AU staff members wont host an Unofficial one any time soon. You can find out more about the official EU clean sweep here but you've probably already seen it, if you'd like to help out you can check the times and dates on the thread!
http://www.mcgamer.net/threads/eu-operation-cleansweep-winter-2016.244200/
You don't need to apply to join the clean sweeps you just need to be available at the appropriate times when the clean sweeps are being hosted. If you're on the teamspeak you will see the staff members in the clean sweep channel and you can poke one of them and they will move you up. If you're not on the teamspeak regularly there should be a status update from on of the staff members participating in the sweep so you can also keep a look out for that.
If an AU mod sees this thread and they would randomly want to host an unofficial clean sweep in the near future, you should see an update from one of them. Just keep an eye out!
If you need help with anything else, just send me a direct message or any other staff member and we can help you out. c:
Thread locked and moved.