Remove all of the pillars and metal fittings on the clarinet. Set them aside in the order you removed them from top to bottom to ensure that you don't get them confused or out of order.
Clean the outside of the clarinet using a soft-bristle toothbrush and water. Avoid cleaning the tone holes as they can be damaged easily. Use the toothbrush to remove large pieces of dirt and debris.
Moisten a cloth with water and rub down the clarinet. Dry the clarinet using a clean, dry cloth. Be careful to avoid damaging any of the keys.
Use a cotton ball to clean out the tone holes. Do not scrub aggressively; just twist the cotton ball inside the hole and remove it to clear and debris.
Apply clarinet oil to a cloth sparingly and rub it into the wood of the clarinet. Take a cleaning rod and pull a corner of the cloth through the eye of the cleaning rod. Twist the cloth around the rod tightly until you have completely wrapped the cloth around the rod. Apply a small amount of oil to the cloth.
Insert the oiled cleaning rod into the inside of the clarinet. This will oil and clean the interior.
Wipe the clarinet tenons with a soft clean cloth. Apply grease, not oil, to the tenons and place the clarinet inside the case to prevent the instrument from being damaged by the elements.