I went through something similar with Coco, but I realized she was freaking out because I would make such a big deal about it, i.e. giving treats, praising, or even talking. I was given great advice by Stacy (Sylvan). She said to just be the leader and be serious when brushing her, without making a big deal out of it. Don't praise, just brush and if she would squirm, I would place her on her back and say NO!, then place her infront of me again, and brush her. It only really took like 3 weeks of just brushing without making a big deal out of that she changed. Now, she just stands there, doesn't squirm cry, or wince. I don't know if she likes it, probably not since once I'm done and I say "OK YOU'RE DONE" she darts away
But she does stand still, even with a knot. Try to just be the dominant one and don't make a big deal. Worked great for me.