Silver goblets: The custom, le-khatḥila, is to perform hagala on silver goblets used for kiddush wine, because ḥametz crumbs sometimes fall into the goblet and soak in the wine for 24 hours, and sometimes they soak in whiskey for 18 minutes (above, 10:13). Since this is a remote concern, if necessary, one may suffice with just rinsing them, in accordance with their majority usage.
The custom is to perform hagala on electric urns (such as those used on Shabbat) and kettles, because ḥametz crumbs may have fallen into them. Hagala is done by filling the device with as much water as possible, bringing the water to a boil in the same manner that the water is boiled all year round, and then letting some water out through the tap or spout through which the water is dispensed. Before hagala, it is best to clean out the stone deposits that accumulated inside. When the lid of an urn is made of metal and one regularly places challah loaves on it to warm them before a Shabbat meal, hagala in boiling water must be performed on the lid.[9]
Thermos: After cleaning it properly, hagala in boiling water is performed. It is also possible to kasher it by pouring boiling water into it and on its opening.
Pop-up toasters and sandwich makers require heavy libun, and since this is liable to damage then, they should not be kashered. (Although we explained above, 10:5, that in times of need we are lenient and allow libun at the same temperature as the usage, since these appliances are difficult to clean, there is no room for leniency.)
A blender that is used to grate, chop, and dice foods – if it was used with cold foods, it is kashered by means of rinsing. If there are grooves in which food particles may remain, the appliance should be cleaned with soap until it is clear that any residual food is unfit for a dog’s consumption. If the appliance was used with hot foods, and one was not careful about using it with ḥametz all year round, all of the parts that touched hot foods should be kashered by means of hagala.[10]
False teeth: These should be cleaned thoroughly before the onset of the ḥametz 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 Pesaḥ.
[10]. If a blender was used with cold, sharp foods (that are so sharp that they cannot be eaten by themselves), and one was not careful about using it with ḥametz all year round, it must be kashered le-khatḥila by means of hagala, as we are concerned that the combination of the strong abrasive action with the sharpness of the food caused the flavor of ḥametz to be absorbed into the appliance (SA, YD 96:1; Kaf Ha-ḥayim 1). If the kelim are made of metal or glass, or were not used with hot foods, then even if they were used with sharp foods, they can be kashered by rinsing them. (We explained in Peninei Halakha: Kashrut 32:12, n. 15, that the special status of sharp foods is the subject of disagreement among Rishonim and Aḥaronim; since our glass and metal kelim do not absorb or release flavor, we follow the lenient view and consider sharp foods as we treat all other foods.)
A coffee machine: One cleans it and heats up water to the highest temperature in the normal manner.
