Front element waxing

[chphoto]

I remember someone saying in the old days they used to apply vaseline on the front element to achieve soft focus effect. I can't see this being too different. Wax has a higher optical density than air and will bend light thus softening the image or creating artefacts.

Top Gear police car challenge, anyone?
Clarkson smeared some on the camera lens and tried to do a powerslide towards the camera, but of course with the amount he applied all you saw was a beige smear with a vaguely distinguishable green blur in the middle of the frame