We got some used silverplated kiddush cups off an online auction. I don’t know who bought or used them originally. They may have been used by non frum Jews. What needs to be done in order to be able to use them? Can they be kashered? If so, how? Do they need to be toiveled? In what order?
You should kasher them first, and then toivel them. You can kasher them by cleaning them very well, especially on the inside, and then pour boiling water over them. They don’t have to be put into a pot of boiling water since they are only used for cold wine.