Another Pinner said: This kept my 2 year busy for an entire hour and my 4 year old busy for 2 hours! YAY! Drop vinegar tinted with food coloring onto a pan filled with baking soda. Sheer minutes of colorful fizziness!!... Pretty sure we will be doing this soon! GENIUS!.
Squirt guns filled with vinegar. Baking soda in the pan. Drops of food color.