When I started cowashing 4 years ago, I noticed a definite increase in hair loss. I figured it was just shed hair that wasn't coming out due to products in my hair. When I stopped cowashing a couple of years ago, I lost much less hair even though I was still using products. A few weeks ago a tried cowashing again for about a week. I lost a LOT of hair. No more cowashing for me.
2C/3A, fine, higher porosity.