Can HempCement be Used for Oven?

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I am thinking of making an oven and am wondering if I could use HempCement in construction. The formula is 5-10 parts Hemp, 1 part lime, 1 part clay, and 1 part SheetRock. This is the formula that I used in chinking my log cabin which over time has setup really well. I was also thinking of adding dimatatious earth to this next mix as I have heard that it makes a very solid result in cement mixes.
The basic recipe is clay, lime and hemp or any vegitation high in silca. It will eventually petrify. I am wondering in this type of application whether it would need to set for many months before using.
Thanks,
John Paul