Labels vary by product; common age indications include newborns and up, 3 months and up, 1 year and up, and some items labeled “All Ages.”
Formulations cover a wide range: many list suitability for sensitive and normal skin, and others also specify dry, combination, oily, or mature skin types.
Typical directions include: pour the product under warm running water (some say a generous amount), add about 2 cups of salt soak and soak for 20 minutes, or use 2–4 capfuls of foaming/bubble bath.
Review summaries commonly report that these products help users relax and improve sleep, often noting a pleasant, calming scent; a majority of reviewers describe relaxation or better sleep.