Based on amount of times I've done the Crota mission for bounties against finding it on patrol, the mission is just the best way, but I got another one earlier and it was on Patrol on Earth in Mothlands. People saying about the Crota mission just mean its the easiest to find the Sword thus the quickest way of getting your chances. Looking for him on patrol can be a pain in the bum especially when other Guardians are around. I've posted previously advising to shoot the minions, then him and finish with melee without getting hit - went from 1 in 50 to 1 in 10 chance of Husk. Just sayin my experience.