Summarize this article:

Take a quick trip down to your local supermarket or pharmacy and pick up a bottle of rubbing alcohol, also known as isopropyl alcohol. Only buy alcohol that is pure and unscented; you never know how foreign chemicals will react with the materials your earbuds are made from. Rubbing alcohol is a cheap, effective way to gently clean and disinfect without making a mess or damaging your belongings.  You can purchase a bottle of rubbing alcohol for just a couple dollars or pounds and it will last you for many, many cleanings (of your earbuds or other objects). Isopropyl alcohol has antibacterial properties, making it ideal for sanitizing objects that have been inserted into the ears or other orifices where germs may congregate. Place one end of a cotton swab into the alcohol and let it absorb. Tap or press the cotton swab against the side of the bottle to remove any extra alcohol saturating the tip. You only need a light coating of alcohol to clean something as small and delicate as a pair of earbuds. The tip of the cotton swab should be almost dry.  Wet the cotton swab with more alcohol as needed, but don't use too much. It's not a good idea to directly expose your electronics to moisture of any kind. You might also think about using an alcohol swab if you happen to have one on hand, although even these can be oversaturated and may need to be wrung out beforehand. It's preferable to use a cotton swab because you can control exactly how much liquid goes on it. Wipe the outer plastic area of the earbuds with the alcohol-dipped cotton swab. The isopropyl alcohol will break down grime that has dried and stuck on, as well as clear away traces of oil and perspiration left behind by your skin. Once again, clean the ear openings very carefully, or avoid them altogether if there is no visible debris built up inside. Use one end of the cotton swab for each earbud to ensure that you're cleaning with a fresh surface. Give the earbuds a pat down with a clean, dry towel. The rest of the alcohol should quickly evaporate and dry on its own. Your earbuds should now be sparkling clean and rid of bacteria and inner ear gunk. Best of all, wiping your earbuds down with alcohol is safe and easy enough to be repeated as often as needed. Happy listening! This is the method that most professional technicians recommend for cleaning heavily-used earbuds.

Summary:
Buy a bottle of rubbing alcohol. Dip a cotton swab into the alcohol. Clean around the earbuds. Pat the earbuds with a clean towel.