Hmmm, night times are hard. Any ideas why he is waking or does he just wake up?
Do you let him have any time to self soothe or do you feel (because of dp) that you have to get up immediately you hear anything? If the latter, it might be worth having a discussion with your dp about not picking him up immediately and seeing whether he begins to settle himself, or doing the pick up/soothe/put down immediately routine for a couple of nights. If you do it starting on a Thursday or Friday night, you will have a couple of nights to see if there is some progress?
Trying to think of other things that might help... we bought a fisher price aquarium with DS1 an older version of this and it really helped as he was transfixed by the lights/bubbles (scarily, I can still hear the tune option it plays in my head).
Have you tried a lamb/sheepskin on his cot?
I do know people who swear by cranial osteopathy as well.
Trouble is, it all ends up costing such a lot of money and in the end it might just be a matter of time.