The 405, on the other hand, has some rather nice spray manifolds, attached to the wiper blade itself. These actually spray down onto the screen, and work brilliantly.
So. Taking this apart:

and using the plastic manifold, and about half of the flexible hose that goes to it, you can do this:

It still uses a bit of the longer leg of the BX plastic manifold, but then changes to rubber just after the clip on the arm. Any 22" wiper blade comes with the clips to hold a 405 washer manifold, as they're also used on some Alfa models too.
The result is that screenwash only goes on the screen in the wiper arc! (woo!)

