To modify the provided userscript for Greasemonkey to hide videos from specified channels and those that have been watched on xvideos.com, you'll need to add functionality for detecting and filtering this content.
1. **Specify Channels**: You'll need a way to define the channels you want to hide.
2. **Tracking Watched Videos**: You could use `localStorage` to remember video IDs that have been watched, although keep in mind this method will only


