Requirement to get Remove switch
1. Mozilla Firefox
2. Mechanic addon
3. Facebook Manuscript
How To Delete All Messages On Facebook
Steps To Delete All Facebook Message In Single Click
1. Open Mozilla Firefox. If you do not have then download it from Here
2. Now set up Grease Monkey addon from Here
3. Reactivate Firefox after setup is complete.
4. Currently login to your Facebook Account( in firefox web browser).
5. Go Here as well as click "Install" to set up Facebook script.
6. Currently comply with steps in Firefox( also shown in picture below) in your Facebook account tab
Tools- > Greasemonkey- > Facebook Message Delete switch.
7. Open up Messages and you will obtain a switch similar to this at the right most side of your close friend name:
This switch will certainly remove your chat with your friend with a single click without any confirmation. Appreciate guys!