Drano is basically sodium hydroxide, NaOH, better known as lye, a very strong base. It will definitely eat your skin if left on but very short term exposure probably won't do much. Different people react differently. it bothers the heck out of me. I'd avoid as much contact as possible. BTW, the slippery feel is it reacting with the esters in the oils in your skin turning them into soap, saponification 8-). Boil fats and oil in a solution of water and drano is the first step in making lye soap. Very drying.