Great thing there’s now a way to delete them, though you’ve got to do it manually. Here’s how to do it on your Android device:
Launch your Google Home app
Press on the ‘Data & Personalization’ button on the left of the page.Click Voice & Audio Activity in the Activity Control PanelTap Manage Activity-this is where you’ll see a list of your recordings as before.
Top-right, click the More icon (three vertical dots)Click on ‘Delete Activity by’Change the ‘Today’ option to ‘All Time’ by clicking the down arrow
Press the Delete button, then OK, then Delete
Google will only allow you to automatically delete your Assistant after 3 and 18 months, because keeping your data in place can improve your experience.