Ds1 was 20mths when i tt him. he was saying "mummy do wee" or "mummy do poo." we went cold turkey and would ask him regularly if he needed to go. the first few days we had heaps of accidents but he very quickly learnt to tell me he was "wep". After that he quickly would come running to me when he needed to go. took us about 2wks before he was able to go all day without having an accident. i would say to give it at least 2wkd and thrn if theres no progress maybe stop and try again in a few more months. hope that helps :-)