Not all Stainless Steel is "Stainless" the higher the grade, the less it will corode. These pieces either have a layer of Stainless on them or are that of a lower grade.
Stainless Steel does not oxidize as fast as other iron alloys because like aluminum it is able to form a thin passive layer on top that prevent further corrosion.
When the passive layer is broken, more corrosion may take place. This is simmilar to waxing of chrome on a car and why it helps.
As mentioned, dipping them in RO/DI water will remove the salt, rub dry.
You can get rid of the rust by rubbing it with 0000 steel wool and using carnuba wax.