Someone gave one of my kids a dough-based circuit activity once. I recall it was hard to prevent the various globs of dough from touching and we burnt out most of our components within a few minutes. The experience was very poor compared to something like snap circuits, or even just using a bread board.
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.
Corrosive salt dough is very much not "the perfect material for a circuit". When you put two wires into salt dough, it becomes a battery; when you pass current through it, that destroys one of the wires.
We wrote up a fun little project where you make a light-up caterpillar using conductive dough, a 9V battery, and LEDs. It’s simple enough for kids to build (and safe with supervision), but still highlights core electronics concepts like polarity, circuits, and conductivity.
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.
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.