When you add an image with "Add media" to the WYSIWYG editor the link around the image automatically gets a rel="attachment wp-att-XX". I would like to remove this with a script - Can anyone help me? :)
You can remove it right before post is printed to the screen by stripping it out from content. But remember it still will meddle in Editor.
I guess you mean instead of this html:
in your editor when you press "Insert into post".
Then you can try to use the filter