Good tips, Mistergreen. I thought the husband was going to scream when he saw me using the marble rolling pin. I bought a cheap pasta maker after that. When I tried similar with firing them, they became more brittle as well. I suspect it's an unnecessary step. Somewhat - I never got into the gel caps. Too much fine motor skills required.
Wallace, it's fun in a going back to childhood sort of way. After the first hour, you start wondering why you started. By the end, you swear you'll never do this again. And luckily, you made so many that by the time you need them again you forgot all about the labor involved.
Oh, and there are reasons you may want to choose the gray over the red. For instance, if you use white sand or other substrate, when you go to uproot if the plant has grown into the clay (which it will) you it will be noticeable. If you use the gray, it's not so much.
I think it works much better. Some of the most popular ones don't even have all the macros needed for growth and they are customizable whereas the commercial ones are not. However, the work involved makes the pre-made ones more appealing. It's a trade off.