Hi Zumba,
I'm not using wipers because I bought the cheap ballscrews but I am thinking of having a greased leather strap/thonging hanging over the groove with a lead weight on it so it tracks with the screw to wipe the gunk off before it gets in the ball nut. I used to use these on my pushbike years ago to keep the axle clean and they last for years on a smooth surface. Not the best solution but it's a start with 2 either side of the nut.
The Neuron.
I am not completely useless.......I can always serve as a BAD example.