I tried the same planting technique as this one four or five years ago, hoping for a few seedlings, but the pot was overwhelmed by massive viability. If just a few had sprouted I likely would have salvaged them in a timely manner. Unfortunately I procrastinated dealing with the mass and through distraction and neglect ended up losing the whole batch. I figured I'd try again the next growing season, but since I have a projects list big enough for four full-time gardeners
(and I have only me part-time), I'm just now getting some started. Once again, it was a matter of just getting some seed in soil before I lose another season!
I just started the seed soaking, but I do have a small but heavy duty pair of scissors. Thanks for the idea; I think I'll go back and see about putting a nick in them. Should be quicker/easier than sandpaper would have been (which I had already ruled out bothering with). I'll still soak the seed for a couple hours after, but it will certainly shorten soaking time. If the seed were fresher, I'd forgo the soaking, but since they are so old, I want to give them the best chance I can.