Rocking Wave Maker

This is 2 bottles of hair gel from the dollar store. I used the gel in a sensory bag project. Fill one with water to weigh it down for the bottom and the other 3/4 with water and the rest with oil. Add water soluble color, like food coloring. You can use an oil soluble color if you want just reverse the water to oil ratio so the color is the majority of the bottle. Glue lids closed well. Glue together perpendicular so the color one sits on it's side and rocks on the other. It looked pretty cool, till it started leaking because I didn't get the lids glued well enough.