Aishi, is your ds sensitive on "being a big boy"? This was the main incentive for F to give up the paci (he gave the paci to Santa last year).
The other thing that works with my ds (not a milk lover either, even if he eats diary) is explaing why he needs a certain food, so I tell him that milk serves to make his bones strongers and longer so he can play and run better and he can become taller. So, if he refuses milk you can insist a bit telling him why you would like he drinks a bit of that and why you are concerned if he doesn't take any calcium source.