I took my sons off him at 8mths, so a lot younger but we went cold turkey he was very attached to his dummy and we were up zillions of times In the night putting it back In, but after 3 days he no longer needed it. We rocked an soothed him In other ways till be was used to it.

Other friend of mine also went cold turkey at 18 mths and they too said 3 days before she forgot about it. Best way is too get rid of all dummies in the house so they can't sneakily find them.