Clearing older chats/sessions to improve performance

I noticed that with the new update, the performance of the chat session is directly affected by the number of enquiries that exist on the chat. It even causes a lag sometimes, up to 10 secs when you type your inquiries. Is it possible to clear some of these older enquiries manually? Even if that means losing some of the data that is used, it is still better than starting a whole new chat and trying to remember what you have instructed over the past months.
Any other suggestion is also welcomed as long as it increase performance.