Silver goblets: It is proper, le-khatĥila, to perform hagala on silver goblets used for kiddush wine and other hard drinks, because crumbs sometimes fall into the goblet along with these strong drinks, which, according to some poskim, causes their taste to be absorbed into the goblet after eighteen minutes (as explained above 10:14).
Plastic baby bottles: It is better to replace them because they absorb tastes at a level of irui from a kli rishon. When necessary, one may clean them and perform hagala.
Electric water heaters, urns, samovars, and hot water kettles must undergo hagala, because ĥametz crumbs may have fallen into them, causing their taste to be absorbed. Hagala in this case means filling the device to the top with water, boiling it, and then pouring it out through the opening generally used to dispense the water. Before hagala, it is good to clean out the stone deposits that accumulated inside. If one puts challah loaves on the lid of the urn to warm them before the Shabbat meal, hagala should be performed on the kettle and its lid.
Thermos: After cleaning it properly, hagala should be performed on it. If this is difficult, pouring boiling water into it and around its opening is sufficient.
Toaster: This requires heavy libun, and since it is liable to be damaged in the process, it should not be koshered.
Kneading Utensils: Rema maintains that such utensils le-khatĥila require light libun, but since they are likely to be damaged, they should not be koshered (451:16, 17). According to Shulĥan Arukh, it is possible to kosher them via hagala. Le-khatĥila, the custom is to be stringent, in keeping with Rema’s ruling (Kaf Ha-ĥayim 451:196, 263).
False Teeth: These should be cleaned thoroughly before the onset of the ĥametz prohibition. They need not undergo hagala, because people do not normally put boiling foods or liquids in their mouths; just as they are used for both meat and dairy when cleaned in between, so can they be used on Pesaĥ. Some believe that due to the gravity of the ĥametz prohibition, they must be koshered in a kli rishon or kli sheni.