[TW]Fox;27859142 said:The clogging up is caused by reactions between different types of fluid, so yes, using the BMW fluid exclusively will make the jets less likely to clog up (Though in theory so will exclusively using any other brand of fluid). The other crucial point is that it's a warranty issue if it goes wrong again and it's only had BMW fluid in.
It won't be down to the washer fluid blocking the jets it will be down to the water you mix it with, unless you use it neat.