Facebook – If I permanently delete the account, will the messages in the friend’s timeline be deleted

Go to your activity log, filter by Your Posts and select delete

Or go to see friendship,

http://www.facebook.com/YOUR_USERNAME_OR_ID?and=FRIEND_USERNAME_OR_ID

And see if the message is there, click the timestamp you should arrive at

http://www.facebook.com/FRIEND_USERNAME_OR_ID/posts/POST_ID and delete the post

If the above fails use this form http://www.facebook.com/help/contact/?id=144040449046092 it's the opposite of what's happening but I don't see why it wouldn't be using the same or around the same feature internally

Your name will just appear as "Facebook User" (written in grey) in the inbox of the recipient. The message will still show, but not from whom. It works exactly the same when someone is blocked. This does not happen instantly, it takes a few days for it to appear as "Facebook User" on the other end.

I've seen this on my facebook profile.