X-Screw cleaning

I am having trouble cleaning my Form 3 (early 2019 model, so is a Form3B supposedly), X-Screw. I have used the cleaning tool provided by my reseller and printed it myself. It doesn’t move along the X-Screw, but rather spins in place and moves the LPU unit. Is the X-Screw faulty?

I have cleaned it with a brush but I’m not happy it’s clean enough, any other ideas? Suggestions to remove the black/old lubricant?

I have had repeated fails, x-axis issues I believe because the screw is proving so hard to clean.