Anyone knows whether can bring buckwheat husk pillows for children to use into aussie?

Australia is pretty strict with what you can bring through their custom. From what I've read so far, buckwheat pillow does not seemed to be on any of their prohibited lists. That being said, as buckwheat is a plant, you may be required to declare it if you are bringing it over. Therefore, there is a risk that it may be taken if deemed as a prohibited item by the custom officer. I chanced upon this link in which you can submit an inquiry on the item you are intending to bring/send to Australia: http://www.agriculture.gov.au/travelling/bringing-mailing-goods/cant-bring-form Not sure how long it will take for them to respond, if you still have some time before your trip, you could consider submitting an inquiry.