The 'Be Witched' quest allows getting the item, talk with the three possible npc's and than you can remove the item and still deliver the quest.

[Papum]

I got the succubus milk to drop wich started the Be Witched quest, than i talked with all three npc's and afterwards got rid of the item.
Had none in my bag but even so it allowed me to deliver the quest and get the followup quest.

Build: 0.8.17