Starting with a cold, unplugged iron, wipe the soleplate with a clean cloth soaked in white vinegar. This will help cut through starch that may be stuck on your iron.
For stubborn areas of starch and dirt, make a paste of table salt and white vinegar. Scrub the area with the paste and a plastic mesh dish scrubber or sponge. Wipe the area with a clean, damp cloth to clean the paste and starch buildup away.
Next, plug the iron in and allow it to heat up. This will allowing any foreign debris to soften and make it easier to remove. You can remove debris using a wooden utensil. Unplug the iron and let it cool. Then wipe it down with a clean, damp cloth once again.
After the iron is cool, coat the soleplate with toothpaste and then let it dry. When the toothpaste is dry, wipe it off with a damp cloth and then buff the soleplate using a dry, soft towel. This restores the shine.