Nothing works to stop dog from barking on walks, what else can I do?

Try having another dog come around that is friendly to play with your dog if possible? if your dog barks at the other dog tell him to sit-or stop when he does reward the stop effort,if he continues give him a squirt from a water bottle then when he stops reward him with a treat and tell him he is a good boy?.You will need to be firm and let him know what behaviour gets rewarded and what does not,it won't take long and he will work this out.Good luck