I'm going to be staying in a village in rural India. I've heard that quarantine is sometimes concerned about dirt possibly bringing things into the country. How likely is this to be an issue?
From the Department of Agriculture - Arriving in Australia page, there's a section for "Other items" that states:
- used sporting and camping equipment including tents, footwear, hiking boots, golf equipment and bicycles (need to be checked to ensure they are clean and free from soil contamination)
It should be sufficient to clean your shoes before arrival in Australia, to remove any soil residue that you might have picked up along the way.
Make sure you do declare your outdoor footwear, so the inspectors can assess them. If you fail to declare such items, and the inspector determines that you should have declared them, you will have further problems.