What a cute idea :D
I will surely prepare this for the next festival of science in my hometown.

Also regarding the vinegar + baking soda mix... One trick that also always leaves little science enthusiasts speachless is one I myself learnt when I was little. If you mix the two ingredients in a tall glass and leave the CO2 to accumulate for a minute, you can basically pour carbon dioxide on a lit candle and it should immediately go out :)
Anyways, great post !