Please consider a "Hide post" function to the Admin/moderator tool set. Not to be confused with unapproved which will go into the moderation queue or delete post which hard removes the post from the database or private which can only be applied to topics and not posts.

Hide post should do just that, hide the post from everybody except mods and admins. Perhaps also add an indicator on the post that tells the mods/admins that it is a hidden post