In a perfect world seed heads are rubbed well first, to separate husks & hulls from seeds.

Out of doors on a mildly breezy day seed with chaff is poured from one tray onto another laid out below it.

Because seeds are heavier than chaff, it falls more vertically. Chaff is more likely to be blown down-wind. Some seed will be carried away. Most will not. Repeat as many times as needed to get reasonably clean seed.

Depending on how much seed there is....

I've broken up the heads from the seeds real well, and picked out the big chunks as I can. Then the rest goes into a sour cream kind of container and while shaking the container, I blow into it. Chaff blows out of the container, seeds stay in the bottom- kitchen table gets covered with chaff, lol.

It's not a perfect form of cleaning, but if it's just a small batch of seed it's not too bad of a way to get it done. And it does not depend on a nice day with just the right amount of breeze or trying to utilize a fan that might blow too hard.

We found that using various sizes of mesh strainers helped get out the larger pieces of chaff. One was so fine that only large seeds fell through. Preparing many different types of seed for a project was a daunting project and we eventually learned that some chaff was not harmful at all. We prepared more than 4,000 packets of seeds. If you want your seeds to look like the ones that come in commercial packages, it is very time consuming without the mechanical blowers and such that they use. Relax, as long as the seeds and chaff are dry - they will be just fine.

One of the neighbor kids came to the door asking if I had any mustard. I went to the office for the seeds and wondered if that was what his mom wanted. I asked him what she wanted the mustard for - and he replied 'hot dogs'. Laughing I handed him an extra jar of mustard.