I don't know how the bleaching process works. I just remember BA and another company said they can have it done on request. So perhaps they are adding the bleach directly to the knots on top. I have no idea. Thus the question.

Not everyone wants injection because there are some inherent problems with it. For one I am not even sure how that would stand up on a super thin skin base. It would probably shed like crazy. Injection sometimes doesn't look natural to people or the hair movement is too stiff .. I never had it so I can't say.