To become a decanter girl, a futa girl is specially fed a specified diet to encourage her massive production of clear nectar. The marble is inserted into her foreskin. Her opening held tight by a rubber band to ensure only the purified substance flows out. This causes concentration of her nectar within. As she fingers her opening it encourages her already available nectar out whenever needed. With a nice ribboned packaging she is ready to serve her purpose at those private owners who are into savoring her exquisite taste~ They called it the geoduck with Pearl~