Temporarily jailbreaking a PS3 help?

[senden]

Alright, so I accidentally saved over my brother's Final Fantasy 13 file. Not a problem, I can just get back up to where he was. However, he maxed out all his characters, so I thought I might be able to jailbreak the PS3, hack in infinite EXP, and just get everyone back to max.

Is it possible, once I've done this, to un-jailbreak the PS3? My brother and I aren't interested in keeping it around, I just want to get this done quickly and then put everything back to normal. Is this possible, or are there permanent ramifications of jailbreaking? For example, if I undo the jailbreak, will we be able to access PSN normally and receive updates from Sony?

[PS3 News]

If the PS3 is JailBreakable (3.55 or below) or if it's 3.6 and you downgrade it first using this complex method (lots of tiny soldering required) then yes you could downgrade/jailbreak it followed by wiping the drive and installing Sony's latest PS3 Firmware (currently 3.66) on it which will allow PSN access.

There are no permanent ramifications unless you tried to use the jailbroken PS3 online (which isn't possible at the moment since the bypass was patched) and Sony banned it.