Now, I love my Amazon Echo, but I also love my privacy. So I like to keep what is stored about me to a minimum.
So for Alexa, to to Amazon.co.uk, sign in and click ‘accounts and lists’. On the right-hand side click’ manage your content and devices’. This will let you delete things you have said, smart device history and manage how your data is stored and used.
With Google, go to myactivity.google.com and sign in. You will then see recent activity across all of Google’s services. Use the filter to view just those for Assistant. Then review or delete entries as you wish. If you remove the filter and go to ‘web & app activity’ you can manage what is or is not collected, such as voice and audio activity.