They really do not need to be soaked before sowing. If you sow them about 10 in a 5" half pot , give them a good drink and then leave them alone until they all show you should get at least 98 % germination. We used to chip the darker ones but that does not seem necessary now. I have had 2 seeds out of 60 fail to show, I singled them out into individual pots yesterday. I have grown them as cordons for over 50 years.