Glow-in-the-dark slime! Another pinner says: glow in the dark slime UPDATE: made this and it was every bit as cool as I had hoped. Not sticky (was afraid it'd be sticky on the hands) and therefore not messy. and it glows!
Indoor Activities for Kids: Homemade Lava Lamps. Vegetable oil, a about of the water bottle, then water. 10 drops of food coloring. Then take a alkaseltzer tab and break it into 4 pieces. Drop one in at a time and wait for each to dissove!