Well I would not suggest using pink noise as it did not change the sound of my Hippo VB. The Hippo VB changed its sound after playing regular music. If this is psychological burn-in, then me, my dad and my friend have all had this psychological burn-in since we all felt the sound had improved big time. Disbelieve me if you will but please dont make fun of something you have not experienced.
I have experienced burn-in all the IEMs I have used till date (PL-30, PL-12, RE1, Hippo VB, Crossroads Woodie 2, Crossroads LBi, Crossroads Bijou 2 and EP-630). The only IEM that I did not experience burn-in was a Crossroads Mylar X3 that I had bought used. Else all the earphones sounded rather bad out of the box and improved in varying degrees after burn-in of about 20 - 25 hours.