To clean the earbuds: Regularly use rubbing alcohol and a cotton swab to clean the sound outlet and charging pins. If possible, please try to use a bulb blower to clean the earbuds - air will be pushed into the port/filter, and the dust/dirt inside the earbuds can loosen and extract debris, then use a cotton swab or toothpick to remove them.
To clean the charging case: Use regular cleaning wipes or a soft cloth with rubbing alcohol to gently clean the charging case.