I can't think of any way.
There is a Facebook plugin for Pidgin, and you can get at your chats that way with a more versatile cross-platform messenger, if you are more normally on other chat services.
https://pidgin.im/
https://github.com/dequis/purple-facebook/wiki
If you want web-based clients, try a multi-app client such as Ferdium, RamBox or Station.