I need a WordPress plugin that effectively locate all images under uploads folder that are NOT set as featured image on any post and pages and delete them, images and its thumbnails. It would be ideal to be able to schedule the process via plugin admin, as a cron job maybe? Please make sure you'll be able to develop an app that is able to deliver expected results, I've tried several solutions out there and none seems to work properly and delete a bunch of images regardless. Image volumes to scan is around 20k images per website. thanks.