I would advise washing it throughly with hot soapy water. Others may tell you it is not necessary but why take a chance. I have taken to washing all my brass prior to reloading, it removes a surprisingly amount of crud from the case. Where I really notice the difference is when FL sizing, the drag friction from pulling the expander button through the neck is greatly reduced. I also do a 50-50 soak white vinegar to water and rinse well in hot water. A 10 minute bake in a 200 degree F oven dries them out nicely.