You can, BUT!!! If you smell gas from your engine bay, you will need to replace them immeadiately. Leaking gas is not something you want in your car!
My personal opinion is that the copper washers are cheap and pulling the fuel rail isn't simple on the MkII because of the air chamber and throttle body (not to mention the vacuum lines). Given the amount of time it would take you to get back in there, I would just replace the washers.