Oddly, I just read that PR myself, and wondered the same thing. A quick Google patent search for "bicarbonate fungicide" will quickly show you what I would imagine are the relevant patents. The sticker/spreader seems to be a specific combination of laurates and sulfosuccinates - although the stated acceptable ratio of one to the other is quite broad. Nothing you couldn't find in any shampoo, I'd bet. Xanthan gum is also mentioned, as is magnesium silicate. Evidently, each has a potential role to play in making the stuff persist on the leaf. X-gum is easy to get at any health-food store. Reading shampoo labels to find a cheap one with the above surfactants would likely get you closer to their patent formula than dishsoap would. Baking soda (although potassium bicarbonate is apparently better,) X-gum, shampoo, and skip the horticultural oil, and you'd likely have a decent approximation of GreenCure for way less. I certainly intend to try it out on the wonderful new rust I have on one of my David Austins.

Dr. R. Kenneth Horst, a reasearcher at Cornell conducted experiments to treat the effectiveness of various fungicides. He found through his reasearch that BS and Hort oil is as effective as the stuff they had on the market at the time. He kept researching and other institutions confirmed his findings. There is now modifications to add to his mix that ramps up the goods. You can make your own or get commercial versions of the Cornell formula.

Keeping in mind that this press release is from a company with a product to sell you need to deterine whether it is something with good, valid information or something to be very skeptical of. Simply because someone prints something, in newspaper or on the internet, does not mean it is true, especially today.