I have heard the oil on skin is best.
This is the best price I have found so far.
Kill two birds with one spray!
For under 7 bucks no shipping fee & tax free...
t2t
Magnesium Chloride Oil
This pure liquid form of magnesium chloride is the quickest and most convenient way to transmit magnesium into the cells and tissues through the skin. For example, a few sprays under each armpit after a shower function as a highly effective deodorant, while at the same time transporting magnesium swiftly through the skin into the glands, lymph channels, and blood vesseks, which distribution it throughout the body. Spray some onto the back of the hands or the top of the feet any time of day or night for continuous magnesium absorption. Regardless of where on the body you apply the spray, once it penetrates the surface of the skin, the body transports it to whichever tissues need magnesium most.