Which treatments for blocked tear duct are most effective?

Massage & Patience: Your pediatrician will show how to massage the nasolacrimal duct. The area to massage is on the side of the "nasal bridge." you can massage the are 3 times per day for 30 seconds each time. It is not very clear how effective massaging is but 90% of these blocked tear ducts resolve by 6 month of age, sometimes even without massaging!

Breast Milk--???: Dr hallaj-pour's answer and comments are right on. An old home remedy which is safe and sometimes helps, is to put several dropsw of breast milk in the affected eye twice a day. I have no idea why this helps, but I have seen improvement in some cases.