Its not a dua its like you do tasbeeh after namz of subhanAllah, astaghfirullah, etc.. its like a ward that you can do for 1000 times on ur hands and touch your face or do dum on milk/ honey and drink it.
It doesnt mean apply milk and honey on face but drink it so it goes in ur body and gives u shifa and beauty or whatever… Dont u know about the dum for sick person? Its like doing some dua and blowing on a galss of water and give it to the sick person to drink.