Washer Fluid

I've been struck down with the usual Octy I problem of the rear washer jet getting blocked and the hose popping off, leaking water into the boot... also the front jets aren't working either and I managed to snap one of the hoses trying to pull them apart yesterday. Now have to take the plenum chamber covers off and faff around trying to unblock everything.

My question is are there any tips for unblocking the washer system? If there are blockages in the hoses as well as the jets then is there a good way of unblocking them?

Going to be using de-ionised water from now on, no more of this limescale-ridden tap water