My windscreen washer wasn't! I cleaned the jets which helped, but still not too good. Checked pipes as best I could (quite a job lifting the lining of the bonnet. I found a pair of long nose pliers helped by getting under the round bit and squeezing the locking devices)
I siphoned off the water after cleaning inside the container with a hose and trying the hot water trick to remove gunk that had accumulated, but was forced to get to the pump. So I removed the front RH side wheel and the wheel liner (first time I had used the jack!), levered off the pump and associated tubes that is press fitted into the container. The pump input has a wire filter that was so full of gunk. I cleaned that after removing same. I found that it fitted inside the house taps nicely so the tap water helped clean it off.
I'm about to reassemble everything again (fingers crossed)