yeah, holding his hand is a prop. BUT, i did it with my first! you know what, if you've struggled for 6mos, and this is getting him to sleep, i say go for it! then you can wean him off it.
1. so right now you are holding his hand till he drops off to sleep and are then gently removing it.
2. when you're ready you can put your hand beside him on the mattress till his eyes start to close and he starts to drift off.
3. then a few days later, put him to bed and just sit there with him till he drifts off.
4. few days after that, put him to bed and walk away. give him a chance to put himself to sleep with a few grizzles, but come back and sit down if he gets too upset.
you WILL eventually beable to just put him down and leave. and for a lot of us (from reading the posts on here) that last step comes about by accident. like you put him down and the phone rings, or someone knocks at the door and you have to go... and they just fall asleep on their own.