You could try a pacifier... although that is controversial for some Moms... and you will have to wean him from it one day. My son had a pacifier. My daughter hated it.
But some babies are just more oral.
Next, try "Spiffies" tooth wipes. It is made with Xylitol, and is specifically for babies and toddlers.
It PREVENTS tooth rot and decay. I have been using it with my kids since my son was a baby. The website is: www.spiffies.com
There are other "xylitol" tooth wipes for kids... which I have also tried, but I like the Spiffies brand the best. Sometimes you can find it on Ebay too. And Amazon.com will be carrying it soon too.
I even use it myself sometimes, to clean my teeth on the go. Very handy.
Instead of milk in a bottle, you could transition him to another "routine" and just NOT put the bottle in the crib. Give him something else to hug/knaw at. Like a lovey. My son had and still has his stuffed Cow... which is his "buddy" and it is all worn and loved and chewed and rubbed. But lovingly.
Yes, leaving a bottle of milk or juice with a child as they sleep WILL damage their teeth. And once decay sets in.... as with my cousin as a baby, they had to cap all his front teeth. It is not pleasant to go through this as a young child/baby.
Or you use a sippy cup of water, as a "chaser" after the milk... and rinse your babies teeth with it.
To feed him when he wakes at night... take him OUT of the crib... feed him his bottle.... and then after that put him back IN the crib WITHOUT the bottle.
A baby WILL wake at night, which is normal... because they get plain hungry as they grow and hit developmental changes... and they go through MANY "growth-spurts" along the way (every few weeks or every 3 months)... and they simply need to feed. As you know, for the 1st year of life a baby NEEDS to be fed "on demand."
All the best,
Susan