I think that's a very reasonable explanation if it spits water. It's not the vapor itself which has no salt in it. Also, you don't need to put salt in the water to make it boil, it just makes it boil at a higher temp.
From some random google search:
Turn that sucker around to face away from the babies!
From some random google search:
Adding salt to water disrupts the bonds between water molecules and slightly raises the temperature at which the water will boil. At standard atmospheric pressure, the change in the boiling point is insignificant, amounting to approximately 0.555 degrees Fahrenheit, or 0.04 degrees Celsius. When impurities like salt are added to the water, the water molecules are forced further apart and can move about more freely, making it easier for the water to be converted to steam. The impurities improve the conductivity of the electrical current, but the impurity does not necessarily have to be salt, which is why some manufacturers recommend adding baking soda instead of salt or advise that if your tap water is "hard," adding salt is not necessary for the unit to function efficiently.
Turn that sucker around to face away from the babies!