When used appropriately, self-moderation is a great way to discourage spammers from even posting in your topic.
I agree. I believe that the self-moderation feature can be useful at times. Still, it should have some additions. The one you, @PowerGlove, mentioned about reserving the deleted posts for others to view can be a good addition, as it will make things more transparent. It will make it clear that the OP isn't removing posts for personal agendas or anything, but the posts are being removed because they deserve to get removed.
Is the creator of the post still allowed to delete the post after this? Or edit it? It wouldn't be fair not to, but this opens up the possibility for a spammer to turn a shitpost into a good post just to make OP look bad.
I think it would be totally fair not to allow the creator of the post to make edits or have the ability to delete their posts once the OP of the self-moderated thread has removed them. Just like how when a post is deleted by a moderator we completely lose access to it, it should be the same in this case, because once the OP deletes your post, it goes into the reserve and can only be seen, but nothing can be done to it.