Mikey P
Administrator
agreedYou're a bit too stuck on this corn rowing thing. If you read the latest IICRC study they do not know what causes it. It's all speculation. As for CRB's causing it, I call bull crap. I cleaned thousands of homes using my CRB with soft brushes and have not had 1 issue. The times I have seen it happen, it was preexisting.
I'v only seen it on crap "California Berber"