Change 1000+ of WordPress Featured Images in 5 Minutes! › Forums › Request a Feature › Hide 'featured image' on post › Reply To: Hide 'featured image' on post
Were the image really embedded in the posts? The plugin has not such a function.
I think it is the theme displaying the image in a post. Just look in your single.php for the line
the_post_thumbnail() and comment it out. This might help.