Speaking of nail oil, we need to separate it from clear nail oil. Clear nail polish is often the last step of a manicure, which is equivalent to putting on makeup with loose powder. The nail oil works as a treatment for the skin around the nail, making it smooth and moist with less barbs and cutin. So how do you use nail oil? Fingernail nutrition oil can besmear on the skin that just removed dead skin, left and right hand massages each other, promote nutrition oil to absorb better thereby.