Mostly the emissions are alpha particles which can’t even pass through paper but CAN fuck you up if the source ends up inside your body. So washing is to remove any small particles that may have been abraded off, same reason you can’t use it if its ever chipped or scratched.
Excuse my ignorance but what is washing gonna do? Also did you tried using a geiger counter?
Mostly the emissions are alpha particles which can’t even pass through paper but CAN fuck you up if the source ends up inside your body. So washing is to remove any small particles that may have been abraded off, same reason you can’t use it if its ever chipped or scratched.
Alternatively: Don’t eat off Uranium cookware?