Self-moderated threads in the gambling section are allowed. However, you shouldn't open such threads if the topic of discussion is someone's reputation or matters related to money. Also deleting legit posts that you don't agree with makes you look bad. Besides, everything that is posted on Bitcointalk will get picked up by Ninjastic.space and LoyceV's scrapper, so deleting it won't get rid of the post entirely. Moderating a thread to prevent the truth from coming out isn't going to get you anywhere.
Judging by your trust feedback, I assume this is going to be a self-modded thread about FortuneJack.
I won't presume thats what OP is up for yet so, I won't judge although, I agree OP has got a case for grievance looking at the amount involved but, its been justified already forumwise.
Creating a Self-moderated threads only to shade free speech or individual views on a two side to a story issue would be fowl play as it hides the truth. So, you could try getting your reasons write and be sure to do actual moderation on the thread so as to prevent spamming.
Other than these, your free to create your Self-moderated on the gambling board and other boards with exceptions to those stated by Z-tight and should you wish to remove the self moderation, moving it to meta and back does the trick.