Oh I thought you needed to enforce on start-up. Yes your idea should work swimmingly. I think you can disable but not hide it. But try it anyway:
oUIObj.SetFolderState(""PCreditCard,PCreditCardW"", ""DISABLE"")
or the ole
oScript.SetUIControl(""fldr.PCreditCard"", ""DISABLE"")
oScript.SetUIControl(""fldr.PCreditCardW"", ""DISABLE"")
PostRead might a better place but give it a whirl and see what works best.