Hair sea salt sprays are popular styling products that are designed to give hair a textured, beachy look. They work based on the following principles:

1. Texturizing: The primary ingredient in these sprays is sea salt (sodium chloride). When applied to hair, the salt absorbs some of the moisture, causing the strands to become slightly dehydrated. This dehydration process leads to a texturizing effect that can make hair appear more voluminous and "piece-y," similar to how hair looks after spending a day at the beach.
2. Drying Effects: Sea salt has a drying effect on the hair shaft, which can help to reduce the appearance of oils, particularly for those with finer hair types. This can result in a matte finish rather than a glossy one.
3. Hold Factor: The salt particles bond with the hair cuticles, providing a light hold that helps maintain the styled texture. This is especially useful for creating tousled or wavy hairstyles.
4. Enhancement of Natural Texture: For people with naturally wavy or curly hair, sea salt spray can enhance and define their natural texture without the need for harsh chemicals.
5. Ingredients: Besides sea salt, these sprays often contain other ingredients such as algae extract, kelp, or other marine minerals that can nourish the hair and scalp. Some formulations may also include conditioning agents to counteract the drying effects of the salt and add shine.

To use sea salt spray, you typically apply it to damp or dry hair and then scrunch or style the hair as desired. It's important to choose a product that matches your hair type and the specific results you want to achieve. If your hair is prone to dryness, using a sea salt spray could exacerbate this issue, so you might want to look for formulas that include hydrating and conditioning ingredients.