I've recently found a blister prevention product which has worked for me. It is made (in the USA ,of course) by Engo, see http://www.goengo.com/
There is not an Australian distributor. The supplier I found which had the cheapest postage is http://www.zombierunner.com/, located you know where. You could ask Engo if they can match that postage rate ($4.33 US) as I had a message that they were looking into that issue.
The blisters appeared after wearing new boots, mistakenly thinking I had worn them in sufficiently. Yes, I wore them at home for a few weeks, then did some day walks; but not a multi-day walk and not with a full load, in hot weather, etc. The boots are basically the same model as the more than a decade old boots I was replacing, so I didn't expect any problems, having never had blisters previously. I have to assume there must be subtle differences in the boot design.
The blisters were on the ball of each foot. I've only done the one walk since applying the pads, so I'll be interested to find out what longevity they have. Interested to know also if anyone else has tried this product.