If the LEDs and whatnot were in modules with polarity protection there might have been something there, but I'm not convinced the dough adds much over just a bag of random components for teaching kids about circuits.
The post includes step-by-step instructions, photos, and some notes on why the dough works as a conductor. We think it's a fun way to introduce kids to electronics or just to play around with a squishy medium for prototyping.