I remember in the old days when the Memorial ended our presiding servant would pour any wine left in the bottle down the drain or flush it down the loo on the principle that it had been blessed and prayed over so could not be treated as ordinary vino. (I never understood why he had no problems flushing such blessed wine down a toilet mind you.)
Nowadays I understand that all the undrunk wine is poured back into the bottle and returned to whoever bought it, so they can enjoy drinking it at home later in the week.
If you were ever on hall cleaning the weekend after a Memorial you usually would find the unleavened bread in the wastepaper basket behind the literature cabinet.
I told that to a friend who belongs to the Roman Catholic church and they were appalled - but that's because they go to the other extreme and believe that it is the actual flesh and blood of Jesus.