I learnt of this trick from a source I can't remember or find any more. If anyone knows who discovered it, drop a line.
Theory: find a battle that has a checkpoint right after it, e.g. after all enemies have died. Kill the last enemy while it is frozen. You will get its orbs. Then, retry from the checkpoint. The petrified foe crosses over, and it can be re-crushed. For some reason the orbs follow you over the checkpoint too, enabling you the chance for infinite orbs...
The video starts with 13392 orbs and ends with 14112 orbs. The trick can be done faster if you don't wait for the red orbs to hit you (done here for demonstration's sake).
At this time, AKheon has 3,136,415 views for God of War II spread across 61 videos. About 2 hours worth of God of War II videos were uploaded to his channel, roughly 1.68% of the content that AKheon has uploaded to YouTube.