Nope, just salt . But don't use table salt , use sea salt or cooking salt .
If you can, use a wide top earthenware storage jar or a large glass jar .
Put a 1/2" layer of salt on the bottom of the jar , then a 1" layer of runner beans , then cover with a 1/4" layer of salt . Another layer of beans and salt and continue to the top . Pop lid on , Job done .