jet washers?

I've notice that I'm getting water leaking from the jet washer and sitting around the spark plug leads on my mk2 focus.It's not from the pipe but looks like it's the rubber seal.I called ford and they said I had to but the whole washer jet-£15.I've heard that this has been abit of a problem with a few other fords but ford do not want to do a recall.Has anyone else had this problem and how did you fix it apart from getting a new jet.Is there a cover that can be bought to go over the top of the engine in case of further leaks.
Any ideas would be welcome.
Thanks,
Bryan