Earthenware utensils as mentioned above always retain a weak flavor, even after they are purged. Therefore, even the opinions that consider chametz to be heteira bala (which as mentioned earlier when a permitted flavor is absorbed purging will permit the use of the utensil since only a weak flavor will remain) agree that they may not be used on Pesach. Since they retain a weak flavor, they also retain their identity as chametz utensils – and therefore are forbidden to use on Pesach.
Note: One should consult an Orthodox rabbi concerning actual practices.
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