Actually it was possible to clone your char with L2walker, too... Anyways:
Cloning PKs and duping stuff on that way is NOT save.
- Since the clones stay ingame untill server restarts, you've gotta hope that no one catchs your dead counterparts.
- Since all items have item-IDs (and it's kinda easy to find similar ones), you gonna get busted anyways.
However, I tested to clone my char - No success till now - But I'm not going to give up.