Delete all updates from an in item conversation

I run a retreat management system that collects lots of personal information about attendees that is required as part of the process of them attending. However, once the retreat is complete I don’t need any of the identifying data but I need to keep demograohic data for 2 years to complete reporting for my donors.

After the 3 month window following the retreat expires I have automations that clear the columns containing names, emails, phone numbers etc, anything that would identify them. However, because there are a number of automation generated emails through the process that get automatically appended to an update on the item conversation, to be completely GDPR proof I want these updates deleted as well. Would be great to have an automation option to delete all updates on an item. this removing all the personal information held there in the form of email addresses, names etc.