This was an excellent informative video thank you for passing this along.I asked @Fitzy about similar questions and he sent me this link pretty cool and I did something similar by accident playing around and it worked for me. I also use sandpaper. Which I guess is also a way of scarification. Cool listen this I thank Fitzy for it.
I am in the process of making my own seed cracker but I also thought about using a pair of vise grip locking pliers because you can adjust the distance that they close.