I had a problem with front and rear jets blocked. I cleaned out the washer bottle of gunk and with a little persuasion and a pin got the fronts working fine. The rear one though is still blocked. There doesn't appear to be a leak in the pipe - it was working quite recently. I tried to remove the rear washer jet to give a good clean but I can't see how to remove it. Its behind the lock mechanism - is removing that the only way to get to it?