You do not want enzyme actve Soya Flour, it is really bitter, and Carp absolutely hate bitter, you want Full Fat Soya Flour from the health shop that doesn't have an extremely harsh taste like the stuff you find in the Winco bulk bins which is green. Soybean Meal ground up finely would be just as good, it is actually one of the main ingredients in most fish foods (Aquaria).
That recipe is pretty much junk food as well, and can also clog up their digestive system, so only use it as a hookbait, it would mainly be a winter bait. In the summer, you can bump your proteins levels as high as 60% (probably even higher).
The healthy recipes that will actually attract Carp in unpressured waters are the ones you find with ingredients you have never even heard of or you have no idea where to find them, they should basically be vitamin/mineral/protein/amino acid supplements that will benefit a Carps health, and should have more than 9-10 actual healthy ingredients (not Flours/Binders), some boilies can be consumed by humans because of the healthy ingredients used.
That guy from that website must live next to a pond that has been over populated with Carp if he can rely on his boilies every session. He doesn't really know much about what he's talking about.