While there is no substitute for dedicated and consistent training, many canine behaviorists and trainers recommend the use of a front-attach (or ‘chest-led’) harness for dogs that pull as they discourage pulling in a force-free way, giving gentle control back to the owner.
Most dogs take to wearing front-attach harnesses fairly quickly too, which is sometimes the opposite for other types of anti-pull devices (i.e. haltis and head collars).
When fitted correctly and when worn only when necessary (for walks and training purposes only), a front-attach harness can be a useful training tool when teaching your dog to walk nicely on the leash.