Halakhah su Levitico 6:21

The Torah (Vayikra 6:21) teaches the laws concerning vessels in the Beit Hamikdash which absorbed “taste particles” of korbanot (sacrifices), and what happens when these tastes become forbidden as notar (leftovers from an expired korban).¹For example, a vessel in which a korban chatat (sin offering) was cooked contains notar taste particles within its walls the morning after the korban was brought. Since it absorbed the taste particles from the korban, the same laws apply to the particles as would apply to an actual offering. Thus, when the korban becomes notar, the vessel also becomes forbidden. The vessel may not be used until the taste particles have been purged from it. The Torah teaches that metal utensils may have their notar taste particles purged by being placed in boiling hot water and subsequently being rinsed in cold water. Outside of the Temple, the rinsing is not necessary, although it is done anyway as a reminder of the customs that were performed in the Temple (see Tosafot, Avodah Zarah 76b s.v. Mikan, and Aruch Hashulchan, Orach Chaim 452:20). The Torah states that earthenware vessels that were used to cook korbanot must be destroyed. The Gemara (Pesachim 30b) states, based on this verse, that the flavor absorbed by an earthenware vessel can never be completely purged. Thus we see that metal can be kashered while earthenware generally cannot. The only way to kasher earthenware is by running it through a kiln (see Shulchan Aruch, Orach Chaim 451:1). Rabbeinu Tam (Tosafot, Pesachim 30b s.v. Hatorah) explains that a kiln does not purge the taste particles, but it recreates the utensil into a new object (cheftza), which has never been used to cook a korban.²I heard Rav Moshe Tendler state that a self-cleaning oven can function as a kiln in this respect. According to Rav Tendler, a non-kosher earthenware dish may be kashered by staying inside an oven for an entire self-cleaning cycle (assuming that the intense heat does not break or damage the dish). Obviously this kashering procedure cannot be used to kasher a dishwasher, since there is no practical way to put a dishwasher into a kiln without destroying the dishwasher. I have heard that Rav Yosef Weiss disagrees with this ruling, arguing that a self-cleaning oven will only subject the dish to intense heat but not actual fire. See Teshuvot Avnei Neizer (Yoreh Deah 110) for a discussion whether libun works because of fire touching the dishes or because of the dishes being subjected to intense heat.