Pair trading is great for temporarily hedge risk in swing trading when trying to pick tops and bottoms. Instead of going counter trade, hoping to be right , you mitigate risk by hedging, with a profit taget 70 percent of the distance between stoploss and entry. The hedge stopless will be equal to the profit target. The loss on the will be considered the primium for averting risk. If you do it at important support and resistances, with a potential upside it is worth it. Think of it in terms of options.
I pair trade every once in a while when one of the stock indexes starts showing a new strength or weakness in relation to the other indexes or at seasonal times when an index is historically its strongest. When you nail them you have a fairly lower risk trade that can run a profit up to a few months.