If washing doesn't remove it how can I ever serve raw spinach again? I don't think I'll be able to trust it, or any similar product, again.
I hope people realize that some bagged salad mixes also contain spinach leaves. This would mean stay away from those bagged salad mixes too.
This statement by the CDC would be irresponsible if all water systems were chlorinated and proper washing methods were employed; as it stands, it is simply to encourage people to dispose of the already purchased but unused product to inhibit the further spread by those who don't know what clean means.
I wouldn't hesitate to eat it if it had been bathed in a fresh properly concentrated chlorinated water-filled clean sink prior to a thorough rinsing with chlorinated tap water.