Flitz is a mild abrasive, 25% of it is a polishing powder. They can call it non-abrasive because its falls 12% below the government standard for an abrasive. I didn't know there was a government standard untill I called Fritz about it once.
If you scrub hard enough it can remove the BB, but like Jaxx said, its a comp finish, so I wouldn't worry about that.
Try CLP, or another type of cleaning oil. That may remove it.
I use CLP on all my knives, works just fine.
Smells nice too!