Abusers choose their victims because they seem to be an easy target. They couldn't care less about you as a person. So, then why would they care if you ctb'ed?
These people will see ctb as an indicator of weakness. It will even increase their feeling of superiority.
What happened to me was not abuse, but people turned away, which hurt. If I ctb'ed, it would just reaffirm that turning away was the best they could do. To me, it would be best if I knew they never find out about me catching the bus. The only way, I could get my revenge is by showing them that I am way better off without them, to make them question their choice to turn away. I failed in doing so, so my last option is ctb. But I know they wouldn't care at all.
Revenge sought from a position of weakness is just pathetic and ridiculous to them. Proper revenge comes from a position of strength. So, again the only way is to recover, let go, and living your best life without them. If you fail in recovering, that's "ok", you can choose ctb for you. But you must accept that the chance to "hurt them back" is gone then, too.