This trick allows you to evolve pokémon that need to be traded by yourself.
Basically, when you try to clone a pokemon that evolves through a trade(i.e. haunter/kadabra), it will evolve when you pull the clone out of the GTS. This also works with pokémon that need to be traded holding specific items, as long as the pokemon that is being cloned is holding the item obviously.
So, to give a brief example, say you want to clone a rhydon and a protector. First you put it in GTS, holding the protector. Do the whole trading glitch stuff. If you're successful, you should have a rhydon/protector in your party and in your GTS deposit. When you remove the GTS one, it'll evolve for some reason. Pretty convenient imo.
Basically, when you try to clone a pokemon that evolves through a trade(i.e. haunter/kadabra), it will evolve when you pull the clone out of the GTS. This also works with pokémon that need to be traded holding specific items, as long as the pokemon that is being cloned is holding the item obviously.
So, to give a brief example, say you want to clone a rhydon and a protector. First you put it in GTS, holding the protector. Do the whole trading glitch stuff. If you're successful, you should have a rhydon/protector in your party and in your GTS deposit. When you remove the GTS one, it'll evolve for some reason. Pretty convenient imo.