>> I become obsessed
Me, too. Then I get frustrated when I find that I can't separate EVERY speck of material either into the SEED category or the CHAFF category. The ambiguous mixtures are frustrating.
"This is MOSTLY chaff, but I bet there's still a lot of seeds there!"
"These are almost all sees, but SOME of specks might be chaff or non-viable seeds!"
So now grab many seed heads and only shake and rub gently, so I don't create a lot of broken-up chaff.
Then I collect "enough" clean seeds for trading and giving away. I know that if I rubbed harder, I would have all that frustrating in-between, hard to clean stuff.
However, I have no regrets about saving lots of "seed-plus-chaff" for my OWN sowing. So after I have plenty of clean trade seeds, I'll give it a few more whacks and some mashing and rubbing, and then clean that until I'm bored or its time for bed. I save that for MY planting.
The first time I cleaned Alyssum seeds, I spent hours on separating out the chaff, and thought that "maybe" there were still "a few" viable seeds in the "chaff" baggie. So I put a teaspoonful of "chaff" on a damp coffee filter ... OK, I got 50,000 % germination, so there wasn't much point in cleaning, after all.
I think the hardest plants to get seeds out of are Salvia. Not many seeds to start and the seeds are hard to get out of the little trumpets, so by the time you have many seeds loose, you also have ten times as much seed-sized chaff as there are seeds.
I cleaned Salvia clevelandii / Cleveland Blue Sage for someone once, and was forced to fall back on picking seeds out one at a time with tweezers.
I keep thinking that I could build a wind tunnel - separator with a computer fan and some cardboard boxes. or something based on static electricity.
