I have a spiralizer that is all plastic, except for the blade which is metal. It is only ever used for vegetables but may have been washed up with chometz dishes.
Can this be kashered for pesach and if so how?
You can kasher the metal tips by pouring boiling water over them. Regarding the plastic, according to many poskim it cannot be kashered, however since you didn’t actually use it for chometz, it may be used, however it should not be washed with hot water or with the pesach dishes. This is because the part that will come in contact with the food is the blade, which was kashered, and any “blios”, won’t come out if it isn’t washed together with pesach dishes etc.
Horav Y. Cahen shlit”a