The Panny FL360 is a clone of the earlier Olympus FL36 flash, so the Olympus off-camera TTL cord will work. I do not believe Panasonic ever marketed an off-camera cord.
I personally use the Canon off-camera cord II, which was a cord I already owned when I was switching from Canon to Olympus back in late 2005. I saw a note on the Olympus forum that the Canon cord worked on the Olympus TTL system so I tried and, sure enough, it worked.
Today, the current Canon cord is the off-camera cord III. I have no idea if that one works or not, but the "II" (only available used now) definitely does. Many Olympus users have used it.
