I have been wanting to grow ground cherries for quite some time, but never go around to sending for seeds. So, when I was at a market in Penn Yan, NY and saw ground cherries for sale, I decided to just harvest them myself, and bought some. I found that stripping the seeds out in small batches works the best.
The harvesting of the seeds is really quite simple. First, you need to remove the paper casing.
Next, squeeze and drop the fruit into a bowl of shallow water
Let sit in the water and allow the seeds to float out. If need be, you can safely manipulate the seeds out of the fruit with your fingers, into the water, without damaging the tiny seeds.
Remove the meaty parts, leaving only the seeds. You will notice that the seeds will go to the bottom. Should any seeds be floating on top, discard those individuals, as they are no good.
Next, carefully pour the water off of the seeds. This is easier than you think, as the seeds will remain behind if you pour slowly and carefully.
You will now be left with the seeds.
Let the seeds dry thoroughly, then either put them with the rest of your harvested seeds for packaging when you are done, or package immediately.