So keep him on leash. And follow Sunflowers advice ... it's not going to stop after three tries ... he's been doing it for some time now and he's been successful. This means he's going to keep trying it because he's been able to do it before (rewarded for his own behaviour)
It might take a couple of weeks for him to get it ... get ONE method and stick with it ... you've tried different methods, and now your dog has not clue what you're going to do when he jumps ... are you going to knee him? are you going to give him treats? are you going to turn your back?
You need to stop him from jumping in the first place, and the easiest way right now is to step on the leash so the can't jump up at all - he can't reward his own behaviour!