Is your feature request related to a problem? Please describe.
The tanning rack is quite satisfying to use, but doesn't have enough applications to remain relevant after the early game.

Describe the solution you'd like
The tanning rack recipes to include a byproduct item and percent chance of generating that item. Rotten flesh, for example, might have a chance of being produced every time you scrape raw hide. This would also allow the tanning system to be used to thresh grain: wheat goes in, dry grass comes out, and each hit has a chance to drop wheat seeds.

Additional context
I realise this may not be very appealing, as it might only apply to those of us using CraftTweaker alongside StoneAge. Thank you for providing innate support, by the way!