I can say that with the touch of the sea shells on the glass bottle, it sounds like a real ocean breeze.
You will need: *Bottle (for bigger kids you can use glass bottle)*Food Coloring *Water *Oil (we used sunflower oil)*Hot Glue Gun
Recipe: Fill half of the bottle with water and add a few drops of blue food coloring. If you want, you can add seashells, glitter, pebbles or whatever you want. Then fill the remainder of the bottle with oil leave 3-4 cm pf gap at the top. Because this is the best way of getting beautiful waves in the bottle. To secure the bottle use hot glue gun.
P.S. You can use baby oil or cooking oil. Both are ok.