IMO my opinion, it doesn't really matter what mom does or doesn't do at home. I have a 10 month old whose parents told me the same as you - will only fall asleep on the cough while drinking bottle. The FIRST day, I rocked her in my arms with a bottle for 5 minutes, put her in her playpen and she slept. After 2 days, I just put her in her playpen with her blankie and a soother and she sleeps. I have a 14 month old who was 11 months when he started and he ONLY (still) sleeps on mom and dad. He sleeps in his playpen here, by himself, quietly. It's all about training.

How long has the little boy been with you? What I would do in your position is move his playpen into another room, temporarily. Place something in the nap room with the others that makes noise so that if the little boy cries, they won't hear it as much. Like a humidifier or a big fan. I find most kids sleep pretty deep, so once they're sleeping, it's usually good to go - in my experience anyways.

Now, you need to train the little boy to go to sleep the way you want him to. For the first little while, rock him in your arms with his blanket or bear and his milk. Then, before he falls asleep, place him in his playpen and sit there. It may take a while, but eventually - hopefully, he'll fall asleep. If it's taking a really long time, leave. See what happens when you leave. Only go back in if he starts crying.

Then, after a few days, give him in his milk and put him in the playpen immediately. Wait for him to fall asleep.

Then, put his milk with him in the playpen and leave.

With my 14 month old, I had to let him cry it out after about 2 weeks. For the first couple of weeks, I waited with him while he fell asleep, but sometime he wouldn't sleep. Letting him cry for a few days seemed to do the trick.

And like I said, for the 10 month old, I got lucky, I guess. She's been really good with napping.

The bottom line is that you need to teach him the way YOU want him to go to sleep, not to let him train you. Start from DAY ONE and you'll never have a problem. Tweak the way you train him to suit his personality. It won't be perfect right away, but it will happen.

Good luck!!