Scuffing the seed allows water to penetrate the outer shell easier making germination faster. The best way I've seen to do it is to roll a piece of sandpaper into a tube, drop the seeds in and, while covering the ends of the tube with your thumb and finger tip, give 10-15 shakes. It's also important to use a sandpaper grit that's in the middle range to avoid over scuffing.
That's clever never knew about that method before will def give that a try
I've never actually done it myself but I've heard that sometimes it's the best way to get stubborn old seed to germ and that some newer hybrids can have such thick shells that it's pretty much necessary.
