Thanks to the mods for making it into a sticky. I am a pc illiterate so once again, thank you
Soy powder?! I think I did spell s.o.y.
You can find them at any grocery store. They are very cheap, as are molasses.
As far as the clogging factor, you just have to make sure whenever you do the periodic maintenance to watch out for the tubes. Check to see if there's anything stuck inside. Sometimes the pressure built-up from the container can force certain 'crud' content into the tubing. You simply squeeze the tube and then pull the stuff out along it. It's very simple. That's about the only downside as far as I'm concerned.
All in all, I think DIY CO2 is a wonderful alternative injection method. I still highly recommend the pressurized system, and view it as a part of the 'rite of passage' of using CO2. Sooner or later, we all should have either or both experiences. It's all part of the integral process that is in our great endeavour in having a lush plant growths!
Paul