.....or, the possibility that this training may have been somewhat similar to Dussack.......a wooden training weapon used for training purposes.
Thus, a training regimen could be produced that gave realistic feedback to blade alignment, plus some resistance training, and a recycleable cutting medium. I dont know clay very well, but could the softness be altered with water to create different levels of resistance? With the addition of armours over clay forms, I think a very high level regimen of combat training could be created.
Ive never done any cutting practice, but it is something that intrigues me. I watched the SCHOLA "First Cut is the Deepest" cutting video on the internet, and I would swear that those guys must have hijacked a produce truck to make that possible. A claylike cutting medium which could be re-formed and reused would make that type of training cleaner, quicker, and likely more "fruitful".
Very interesting idea.