Any of those programs will also “flunk out” unsuitable dogs. Also, some of those programs DO use punishment in their training (though many are moving away from it now). I’m not a fan of shock collars, but that’s not the best example of why they’re largely unnecessary.

A muzzle would have been a much more effective tool for the pittie in question. Not only did that pittie have a shock collar that was used wildly incorrectly (punishing the dog for stopping the attack!), but the shocks can also stimulate the dog into attacking more aggressively as it thinks the other dog is hurting…

Positive reinforcement cannot, by its very definition, decrease a behavior. It can, however, increase an incompatible behavior. In your barking example, I might work on encouraging the dog to sit quietly on a mat in the absence of the stimulus that’s causing the dog to bark. As the dog becomes proficient at relaxing…

The easiest way is to provide an area where the dog is allowed to dig - don’t forget that digging is a natural and enjoyable behavior for dogs. Encourage digging in that digging box with praise/treats and buried treasure (toys hidden in the dirt). Put digging in the box on a verbal cue and direct the dog to its box if…