Set the iron on the automatic steam setting.
Fill the iron with water, set it to the highest steam setting and plug it in.
Place a metal cooling rack on a surface that will not incur damage from heat or steam.
Set the iron on the metal cooling rack with the sole plate resting on the metal. Allow the steam to flow continuously from the iron, which will clean the steam holes. The heat of the steam will also loosen scale and force it out of the reservoir. Repeat two to three times if the iron has a heavy scale buildup.
Unplug the iron and allow it to cool to room temperature.
Mix warm water with a squirt of dish soap in a bowl.
Dip a rag or sponge into the soapy water wring out excess so the rag or sponge is wet but not dripping.
Wipe the sole plate and housing to remove dirt and buildup. Dry the sole plate with a rag. If the buildup remains, mix water and baking soda to form a paste. Dip a damp cloth into the mixture and rub it onto the sole plate. Scrub the stains until they are no longer visible. Wipe baking soda residue away with a damp rag. Dry the iron.