One more thought.  If I remember correctly, the vaseline technique could be used at either the photograph stage or in the printing.  If you smeared it on the camera, it was primarily the highlights that went fuzzy.  On the enlarger (printing), it blew out the shadows.

If you are trying to replicate a specific effect, the blur functions and layer blending should be ok, but you'll probably have to use different degrees of blur for shadows and highlights.  The example used vaseline at just the photo stage, I suspect.

Either method was intollerably sticky, but the smudge was more controllable than stockings.  So multiple layers with different degrees of smudge might be worth a try.