We found this Chewing Gum Kit on clearance. It was fun. It's not too messy since you melt the gum base in their disposable bowl, plus I used a disposable spoon. Other than that, you get powdered sugar everywhere. The gum looses it's flavor quickly, but if you've chewed store-bought natural gum before, you'd expect it. I'd recommend buying some natural gums & regular gums to sample the differences. Some educational information came with the kit. It talked about how natural gum comes from the rainforest and how it provides jobs and reasons to protect the trees.
The next day we watched some YouTube videos on how gum is made. Our favorites were: