In a mixing bowl, thoroughly combine 1 cup of baking soda, 1/2 cup of citric acid, and 1/2 cup of cornstarch. Whisk until uniform and powdery.

Pour 10-20 drops of your chosen essential oils into the dry mixture. Stir well until evenly distributed.

Gradually add a few teaspoons of water or witch hazel while continuously stirring until it resembles damp sand.

Pack the mixture firmly into silicone molds. Ensure they're tightly packed to prevent crumbling.

Let the molds dry in a cool, dry area for at least 24 hours until hardened.

Gently pop the steamers out of the molds and store them in an airtight container.