I had the NG 1.1 and I used to use a Sound GUard mat to scrub the record on before the vacuum stage. I found that the Sound Guard mat held the record in place and allowed me to really bear down with the brush to lossen all that would come off. I did upgrade to the VPI 16.5 and can do that scrubbing on the platter now. But one more thing is I bought the Needle Doctor Scrubbing brushes too. I found those worked much better than the NG Brush.
Good Luck!
Good Luck!