I have inoxia out in my raised bed of deer proof plants and my blooms are white, fragrant and do spread out large and have cropped up like re-seeding, but I've not had luck using the seeds on purpose. blomma, is there a technique, or best time to gather, dry, etc.
I let my bluebonnets dry on the plant, gather, soak before planting.
I have a great pic of my new purple and white double gift datura which by your def is a metal.
Yes, there is a right time to gather the seeds. They have to be ripe. Usually when they are, they dull in color. However, you can watch the pod and wait for it to crack. I usually surround the pod with cheese cloth since when it is ripe it spills seeds all over.
Spread the seeds out on paper towel and allow to cure for 2 weeks. Store in plastic bags, or other sealable container.
Soak the seeds over night in hand hot water. Cut in hald and wet a kitchen paper towel, squeeze out excess. fold it into a square. Place your seeds inside and fold one end over. Place this package in a ziplock bag. Place it at room temp or above to germinate. That they do very erratically. Can take up to 20, or more days. Check your package every 3 days. When you see them sprouting, transfer to potting soil, using a tweezer. Be sure to plants so that the tiny root point down.
I don't have photos of sprouting Datura seeds but here are Columbine seeds I started with the above method. The only difference is that those seeds were placed in the frig for 3 weeks for stratification (cold treatment)