I'm actually thinking of starting to sell refined versions of these bags/tubes since they work very well. Here's my idea:
The idea is to sell a kit that includes the base tubes, which are like most fabric pots but they breathe a lot better and are completely UV resistant for outdoor/greenhouse use, filled with a media of my creation which is 2 types of peat, 2 types of perlite, coir, sprinkle of Dol. Lime, a specific grade of Zeolite for insanely high CEC (particularly in Phosphorus which is never available enough from my testing, despite using high-P ferts) and some other hidden goodies. My plan is to sell these with full instructions and with the granular fertilizer (thinking about a 100:1 concentrate since folks like liquid nutes and I can keep the FeEDTA in solution at that concentration) I've developed off Chatelier's formula which works incredibly well along with the specific capillary fabric that keeps everything evenly watered to a distance of up to 30 feet. I think I'll be able to sell it for less than what rockwool slabs cost, but the customer gets nutrients, the fabric, etc. The results are always great and disposal is far less of an issue than rockwool. You can top feed it, bottom feed it, wick irrigate, drip irrigation or even shove them in NFT troughs and turn back the timer to once every 12 - 48 hours (depending on conditions) instead of the usual 15 min on/15 min off that NFT uses.
The idea is to make it so that anyone can grow spectacular crops with a high margin of error - something that's is missing with most hydro setups (aeroponics and DWC come to mind).
I've made a few production-quality units in the past couple weeks that really look professional (i.e. no ugly white huge zip ties on the ends). as a side note, I've got over a dozen years experience in various horticultural fields on my resume for whatever that's worth.
Let me know your thought on this and feel free to play "devil's advocate", it won't hurt my feelings and it may expose errors in the system design that I may not have thought of.
Thanks!