cradle cap help

So baby boy has cradle cap. I've dealt with it before with my daughter. With her, I put lotion on her head and comb/brushed it off and she was good to go. With my son I have brushed it dry and with Vaseline. Both times I have made him bleed and now I feel horrible. I don't know what the problem is. Anyone have any ideas on how to get rid of it without combing it off? I hate to make him bleed for something so silly as this.