Make Your Own Cute Bath Fizzies

you can also find citric acid in the kosher aisle your grocery store, labeled as 'sour salt'.
I found the ingredients -- citric acid, especially -- in the canning aisle at Walmart. I also bought a nice silicon candy mold there.

Sift 1 3/4 cup baking soda, 1 cup citric acid, and 2 cups cornstarch through a sieve to remove chunks. To make different tints, fill small spritzer bottles with water and add about 6 drops of food coloring to each.

Pour 1 cup of powdered mixture into a glass bowl. Lightly spritz, stirring after each spritz, until powder is desired color. Add water slowly, so mixture does not fizz. If mixing two tints, alternate colors as you spritz.

Check the consistency of powder with your fingers; when it can be tightly packed or shaped, stop spritzing (this may take a little while).

Select an essential oil. Add 5 drops if it's one of the stronger scents (peppermint, lavender), 6 if it's a weaker one (lemon, grapefruit). Mix well. Firmly pack mixture into small baking molds. We used 1/4 cup for each fizzy, which is good for one bath.

Allow mixture to set for 2 hours, then pop out carefully. Repeat with different tints for remaining powder. Then place them in nice jar to keep fresh longer and they make a great display in the bathroom. Enjoy ! :)