Ah, now this is a common misconception. Magnesium chloride is in a liquid form, and is not mixed with an oil as such. It is commonly known as magnesium oil because the liquid has an oil like consistancy, but does not contain oil, just the magnesium salt and some other trace elements and minerals.
It has a bitter taste, and if you use it on your skin it can sting if you have any open wounds. It can be used as an antiseptic, but its gonna hurt.