I acquired a used blender from someone I assume was a non-jew. The blender is made from plastic with metal blades. This is a small blender, the kind usually used for making smoothies rather than hot soups, but I don’t know how it was used. Does it need any sort of kashering (besides for toveling)?
Yes
Just cook up some water and throw the blade in while its bubbling and then take it out and put in cold water.