Bloke at work got a ticking off from the police yesterday…he had cleared the ice from his screen but they stopped him due to salt build up that he was unable to clear due to frozen washers. Can't have been that bad as he only has a 5 mile commute!
I've seen photos of cars where people have extended the washer line, and wrapped a section of pipe around a coolant pipe before continuing it to the jets. Obviously you have to identify a pipe before the thermostat otherwise it won't get hot for ages…
Won't help defrost the jets themselves though. Maybe they need a redesign…if that last unheated section of pipe was able to self drain through a one-way valve, there would be nothing to freeze 🙂 There would just be a short delay whilst the pipes refilled before getting a squirt of hot water.
Like skidartist, my van has pipes across the wipers rather than bonnet jets…they normally stay frozen all day.