To make this achievement less of a drag, occasionally throw rocks near enemies before you decide to kill or move past them during your playthrough. When I actually decided to go for this achievement it only took a few tries because I usually threw a rock before I engaged an enemy.
Also, I don't think it matters if you kill an enemy or not after distracting them with a rock. As long as they move towards the rock, look around, and return to their original position, it should count towards the achievement.
163/164 games completed (including DLC)
Completion percentage: 100%
Latest retail completion: Dragon Age II
Latest arcade completion: Dust: An Elysian Tail
Currently Ranked #1 on Achievement Completion Percentage Leaderboard on TA