This is a memo on how to bulk delete files in Drupal. The following was helpful.

Drush - entity:delete
A command line shell and Unix scripting interface for Drupal
www.drush.org
 
drush entity:delete file

I hope this serves as a useful reference for situations such as when files can no longer be viewed due to errors like Drupal\Core\File\Exception\InvalidStreamWrapperException.