We muslim people took nigella sativa as an "all in one" medicine. I ate and drink the black seeds and still alive and healthy until today. The best combination is honey and nigella sativa for your medicine consumption. You won't need to go to doctor, but please learn how to prepare the dosage.
Nigella seeds are pretty tough. I'd probably try rolling them over in a ziploc bag with a rolling pin, very gently. Then sift the seeds with a sieve with proper hole size. I'd wear goggles working with them.
I could never separate the chaff this way as I have severe asthma. I’m getting ready to plant these seeds for the first time myself. From what I have learned from your video, I think I will spread the seeds on a baking tray, then use a fan to blow the chaff away from me. Thank you! 🌻
Yes these get sown at the sane time as the other cool season flowers. They are prolific self sowers for me so I haven’t actually planted any in at least 5 years 😂 they just grow in their own!