Bicarbonate Soda and citric acid
This ingredient is such a multi purpose one and is used in the bath products by Arlie Girl.
Citric Acid is used in cosmetics to lower the ph in formulations, and is used in soaps to provide better foam and water-softening. Citric Acid is combined with baking soda to create bath bombs (fizzies). You will find Citric Acid in the Arlie Girl bath products.