When doing the "rope trick", be sure the cylinder was at TDC ready to fire. If you use the other TDC, one or both of the valves will be partially open, which might possibly cause damage to the valve, etc.
But I just use an impact wrench. If you don't have an air impact, then a BFH and breaker bar will probably work as well.
Either way, you need a 6-point socket in the right size. The dog bolt doesn't have sharp corners, so a 12-point socket may not grab it securely. I don't recall the size offhand, maybe someone else does.