Hi @Stephen Bidgood , you can go to sys_cs_collab_chat table to manually delete the conversation. The deletion of the record can trigger cascading deletion on other related recordings, including messages, attachments, etc.

You can also define your own policy in servicenow table cleaner. For example, you can define a rule to delete the chats if the tasks associated are closed and there are no activities in the chats for 30+ days.