To delete your Grok chat history, go to grok.com/app and remove messages...

https://telegra.ph/How-Do-I-Handle-a-Stubborn-Grok-File-That-Wont-Delete-07-13

To delete your Grok chat history, go to grok.com/app and remove messages directly from the conversation. Don’t forget to check the Recently Deleted folder—it holds your deleted chats for 30 days before permanent removal