I shampoo and dc 2x's a week. Once a week after I seal my braids, ( the entire braid-not just the end), I dust my ends. And seal again. I do this every week.
As a result I have no split ends or knots on the ends of my hair to deal with. Yes, sometimes when I dust the ends I take off are smooth and undamaged. But the amount I dust is so tiny it does not make a difference in the overall length of my hair.
My hair is growing at a good rate and my split/knotted ends problems are now non issues.