If you follow the rules in the article, you have an approximately 50% chance of getting a pair. If you go to the store, and watch a tank full of them, if you watch closely for a while, you'll see that some of them have naturally paired off. That's your best bet (though it's a challenge keeping track of both of them in the chaos of catching them). At one of the stores I used to go to in Omaha, they would catch and separate those pairs, so they were easier to track down when someone wanted a set.