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

https://www.bookmarking-online.win/to-delete-your-grok-chat-history-go-to-grok-com-app-and-clear-conversations

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