I've always used the loop method with chargers and adapters, because of my decades as a musician dealing with various kinds of cables. When cables fail, it's invariably at one of the two ends where the cable gets bent and twisted. In fact, a bad cable can almost always be repaired by cutting off a couple inches from each end and re-attaching the plugs. Strain reliefs of various types help prolong the life of a cable, but not really by very much.