Hi enitharmon - thanks for the encouragement to all the people who posted in this thread. Hopefully slowly but surely some more people will have results (positive and negative) to share.
I haven't tried the sugar additive (I thought he used that to increase the amount of microorganism in order to increase slipperyness. I'll have to reread the patent. I sort of assumed this was just one of those throw away lines used in patents as I don't think it was actually listed as one of the patent claims, but you're right - worth a quick experiment).
With regard to the joining of pieces of bronze clay - I sort of tried cross-hatching (although not as well as I could have), adding bronze clay "slip" to the parts before joining, and also left the small figure in a plastic bag for a couple of days to equilibrate the moisture, followed by slow evaporation in the plastic bag with only a few holes, before removing the bag etc. No joy. Cracks still formed. However, this may still be just a matter of technique. Read in another article that in order to avoid cracking of ceramic greenware, they did the initial drying of their green body at 90% humidity for 24 hours when most of the shrinkage occured, followed by normal drying.