Elphaba's Green Elixir (Wicked Foam) A magical potion that creates a huge, fluffy green foam cloud. Materials Needed The Container: Pink Paper Cup: (Represents Glinda). Draw a magic wand on it with a black marker. The Reaction Base: Baking Soda: 2 Tablespoons. Egg Whites: 1 Tablespoon. Secret Ingredient! Unlike dish soap, egg whites create a firmer, "meringue-like" foam that holds its shape better. Alternative: You can still use Dish Soap if you don't want to use eggs. The Magic Color: Green Foo