As Porter said, any orders that go through official channels will be "flashed across the wires" immediately.
That's why Lincoln's secret orders to paralyze the Sumter mission did *NOT* go through official channels. If they had, the Confederates would have known it was a ruse, and wouldn't have saw it as a real threat.
It would have made no difference, the Charleston authorities would have fired on a girl scout canoe if it was flying an American flag.