I am using dummy for sleep, and it's great! She won't take it at any other time, so I don't offer it any more. Only for sleep. She knows it's a sleep sign now. Also with No 1 I used a dummy with her until she was about 3 and she was a FANTASTIC sleeper (after 8 months) so it never caused a problem. When you want to get rid of dummy later, if they're addicted, it is possible, just takes persistance, can be gotten rid of in a day or two. I wouldn't worry about that though, just do what helps now. It hasn't effected our feeding in any way either! xo