The shore excursions desk on board told us this information. They said that each person in the group would chose one scent and they would be combined to make 1 vial of perfume. Like a blending of the family to create a unique scent. She also made the snotty comment of "where does it state that each person makes their own perfume?".
Hope this helps... It seems on this sailing that one person says one thing, and another says something else. I couldn't find anyone that did this tour so I can't confirm this. If any Dis'ers actually did this excursion please let me know.