That cloning glitch was usable when X/Y first came out, and for a while after that, and so people were able to do ridiculous stuff, like making seven more Clones of a shiny Mew... (true story - my friend did that when he traded a shiny Celebi for it).
Eventually there was a system update that patched the glitch - you could still do it, but it wouldn't give you a clone; only the two that you were already trading in the first place. And, if you didn't update your system, then it would tell you that you had to update it before you could trade with anyone.
So there was no way to get out of it.
Since then, Omega-Ruby and Alpha-Sapphire have come out, and now Sun and Moon, but I don't think that glitch is going to work anymore. Technology is only improving as time goes on, meaning there will be less malfunctions, not more, and I don't think that Nintendo is going to "un-patch" that glitch, because that's not how it works. :r
I know the answer sucks, 'cause I'd be super happy if that still worked, but I hope that it answered your question, at least, even if it wasn't what wanted to hear. :/