All right then. In the 5th century, Anglo-Saxons reoccupied the old Roman hillfort of South Cadbury (a traditional site of “Camelot”). Modern archeologists discovered finely made kitchen pottery that turned out to be … get this… re-used Roman funerary urns! For KITCHEN pottery! And how do you think the Anglo-Saxons got hold of said pottery? They raided local cremation cemeteries and so knew exactly what those pots were that held the castle flour supply.
Certainly the Anglo Saxons re-used pottery from earlier cultures and in Kent they used Roman funerary urns too. But heh, they used them for new burials and not, say, tonight’s dinner!