1,128. Kashering (or Not Kashering) Certain Difficult Vessels

Chometz u’Matzah 5:25

Earthenware utensils that were used for chometz in hot water, whether for cooking, such as pots, or for eating, such as bowls, regardless of whether or not they are glazed, may not be used for matzah. They must be put aside for the duration of Passover, after which they may be used as per usual.

Chometz u’Matzah 5:26

Let’s say that one has a pot that he wants to kasher for Passover use but he cannot find a larger pot in which to boil it. In such a case, he may put clay around the pot’s rim on the outside and then fill it with water until it overflows. He then boils the water in the pot and it is sufficient. Finally, he rinses off the pot and it may be used for matzah.