Hi Glenn, FWIW I put together my first raft over the weekend and just puts seeds directly in there (a variety of stuff) to see what would happen, the majority of them have sprouted even though I expected them to either fall through or drown.
I put perlite and hydroton in my deep water culture system, and they produced great squash starts: this is hydroponic.
I just posted a pic of our net pot setup on our public Facebook page:
We're trying to use only gravel and a piece of wicking cloth (to get seedlings started, until they have long enough roots). Pretty simple, we'll see how well it works.
Someone once recommended using a cotton mop as wicks. I cut off a few strings, tied them together, drew one through the net pot far enough to reach the water and smashed the rest into the pot to create a spaghetti mess of sorts. I sprinkled in a few seeds and put them in an NFT pipe that came from my rock media bed and drained directly back to the fish. I had surprising success with many seeds. When they're big enough, they can go into the media bed or DWC. It would probably work to start directly in a DWC. Just an inexpensive alternative.