I'm not sure which sites you were referring to OhHenree but if you notice when you make a reply, up at the right hand corner there appears three tiny dots. Putting your pointer on those dots and pushing the mouse button, You can delete your own comments.
Just for fun try posting some nonsensical garbage and post it. then go back and find those three tiny dots up on the right hand corner of your posting. You should be able to delete your own nonsensical garbage. I think that in place of your posting a message will appear stating that your posting was deleted by you. Other comments or postings from other members will not have those three tiny dots except on their own postings.
Maybe AN "X" instead of three dots to delete your messages.