The wet cloth steaming method is widely used amongst luthiers. Have used it very successfully. But instead of my wife's iron, I prefer to use a 100W soldering iron. A deep dent may require a couple applications.
For any finish touch up, I let the wood dry throughly, lightly sand with 220 or finer sandpaper (or even a scotch pad), and applly several coats of Minwax's wipe-on poly finish. Using either satin, semi-gloss, or gloss, depending on what matches the existing finish. You will probably always know it's there, but short of a complete strip and refinish, it is your best bet at restoring the damaged area.