Dai Ko Myo means, "Divine Light of the Universe, Shine on Me." It is a more powerful force than Cho Ku Rei, but works the same way. Dai Ko Myo pulls energy directly from the Spiritual Plane for Healing. Cho Ku Rei does use the same energy, of a different vibration. Dai Ko Myo, because it works with the Spiritual Plane and Spiritual Body directly, can heal more deeply, often eliminating deep seated pain.
In practice, Dai Ko Myo is used the same way Cho Ku Rei is. The only difference is that Dai Ko Myo works at a deeper level, so the healing is more powerful.