What needs Tevilla?
Utensils which are used for eating or for preparing food require tevilla. Those utensils that are used in early stages of preparation of food do not require tevilla, for example equipment used to harvest food and equipment used to sift flour.
Only utensils owned by someone who is Jewish that were owned at some point by someone who is not Jewish require tevilla.
Only metal (including alloys) and glass (including pyrex, duralex, corelle) utensils require tevilla. Some people do not toivel glazed chinaware and some toivel it without a brocha. Most communities do not toivel any plastics, while some communities (Chabad and Breuer’s) toivel hard plastic without a brocha. Being that aluminum is only found as bauxite, and must be processed to become a usable metal, some people do not say a brocha when toiveling aluminum, while others say a brocha.
Some Rabbonim do not require tevilla for equipment that can only be used if it is plugged in, particularly if immersion in water will damage the object.
Tevilla Preparation
Stickers, tangible dirt, and caked on food must be removed prior to tevilla. “Goof Off”, ammonia, nail polish remover, scouring powder, scouring pads, and lacquer thinner are useful for removing stickers and other “chatzitzos” (dirt etc.). Make sure to use these items in a safe manner. The items should be cleaned before reciting the brocha.
Method of Tevilla
Wet your hands or any basket you are using to hold the items. Say the “brocha” (if only one item is being “toiveled” some people say “al tvillas kaili”). Do not speak about non-tevilla related topics until finished.
A utensil must be “toiveled” all at once (not half at a time). Shake the holding basket so that the water touches all areas of the utensils. Make sure that any air trapped in the utensil is released and replaced with water. A child or non-Jew may help with the tevilla if an adult oversees them.
A few examples: Baking pans, racks used for grilling, apple peelers require tevilla with a brocha. Teflon coated baking pans should be toiveled without a brocha. Oven racks, meat thermometers, can openers, and cork screws do not require tevilla.
When in doubt say the brocha on an item that requires tevilla and include all the questionable items. As with all matters of halocha, follow the advice of your family rabbi and the traditional “minhagim” of your family and “kehilla” (community).