Clearing old Google results boils down to one question: do you control the...

https://sierra-wiki.win/index.php/How_to_Fix_the_Ghosting_Problem:_Removing_Old_AMP_Pages_from_Google

Clearing old Google results boils down to one question: do you control the site? If it’s your site, delete the page and ensure it returns a proper 404 error; don't leave it as a soft 404 or Google will keep it indexed