Cat hating and chasing

Our staffy cross is a rescue boy, we have had him approximately two and a half years, and in that time he has been quite a handful as he didn’t seem to have been socialised very much at all. He loves other dogs though, and always wants to be chased by them. Over time his behaviour towards cats has escalated, and on his afternoon pavement walk he knows where they all live, and reacts very aggressively, so much so that we are pretty sure he would hurt a cat. He lunges in the direction of the cat, and it takes all our strength to control him! At the moment we are trying the Ceaser Milan method of making a noise at him when he starts looking, and when he starts to lunge telling him off and trying to get him to focus on us, sometimes this works better than other times! I wondered if others have this problem, and if so how do they deal with it?