Don't pinch. No need. If you pinch too hard, you crush the embryo.

If having a hard time trying to get the seed to germinate, lightly 'scuff' the seed with fine sandpaper. Along the seeds suture (ridge, edge...whatever you want to call it) is where I 'scuff'...just enough to remove some of the natural waxy coating that protects the seed) This allows the seed to absorb water, and start the germination process. :thumbsup: