Alcohol swabs/wipes tend to be used for cleaning skin areas before beginning of a procedure. When you wipe an area with alcohol it kills the bacteria then evaporates on the skin. Therefore making the skin area ready for you to use with tapes, pencils, markers, ink and razors.
They're an essential part of most cosmetic tattoo procedures and are pre soaked with 70% Isopropyl Alcohol. They are individually foil wrapped and easy to open.