The lack of ions in the water would play a small role. I suspect that milky suspension was stable because of some detergent (molecules with hydrophilic and hydrophobic parts) in the oil. A layer of those mollecules on the surface of a water droplet can stabilize it.
But you could try the experiment yourself. Only a small amount of oil would be needed, so as not to waste it and make more polution.
Mike W.
(published on 09/20/2020)
