This weekend we rebuilt it using clay from the garden - though we bought the sand in from offsite. Everything else was recycled (bricks, chimney flue, firebricks etc)
We're intending to lime render it.
Pics and more info on http://www.waark.com/2013/05/earth-oven-version-2/

My friend Tiff Heaver sculpted the dragon, there's still more work to do when I get round to applying the lime render