TO Original Poster.
How does this work..? It can't.
think about it
1. your pokemon goes to the pokewalker.
2. it saves the game, so your game knows what pokemon is away in the walker, what route its on etc.
3. when you go to return it, the picture of the pokemon that is in the walker appears.. so when you go to return your pokemon from the walker it can sync accordingly.
so whats wrong with that?
well if you turn it off during stage 2. it wont be able to access stage 3? Why? because if it doesnt save the fact that the pokemon that is away in the walker you cannot return it, simple. It will still be in the box where you last saved your game properly. The pokemon in the walker is considered glitched and trashed.
Try it and let me know.
Nintendo and Gamefreak didnt fail here, the person who came up with this did.
In all proper versions of the game, this glitch does not work.
Cloning pokemon is bad anyways. It ruins the game completely, IMO.