A 2005 study by the University of Kiel in Kiel, Germany, showed that the primary minerals in the Dead Sea, one of the most famous sites for people seeking health benefits, are magnesium salts, and that subjects with dry, rough and red skin achieved positive results after soaking their arms in Dead Sea water (as opposed to regular tap water).
Even though it might seem backwards to moisturize your skin with salt water, it really works. The key is magnesium salts. Regular table salt won't have the same effect. Research labs all around the Dead Sea study the effects of Dead Sea salts and mud on the skin, and they've found that the mineral compounds improve cellular metabolism, stimulate circulation and can even protect against UVB radiation. They also moisturize the skin, reducing roughness and inflammation.
Magnesium salts moisturize the skin through a process called osmosis. The minerals are hydroscopic, meaning they attract water. When you put these minerals on the skin, they attract water from deeper levels of the skin up to the surface. Your skin is moisturized from the inside out. The salts also provide another way for the moisture to stick around -- they exfoliate. They very gently remove dead skin cells from the epidermis, leaving the skin open to the absorption of nutrients and moisture. Mineral salts work best with warm water, which is why a good mineral bath soak is so effective. Warm water also increases circulation. More positives? The salts also provide relief from skin disorders like psoriasis and eczema. They help fade bruises, remove splinters and soothe sunburn.
By the way, you might know magnesium salts by their more common name Epsom salts. A one-pound box will set you back about two bucks. See? A luxurious, healing mineral bath need not cost a lot of money. Of course, it's more picturesque and exciting to visit hot springs in person, but Epsom salts will do the trick right in your own home.