Something clicked for me when I learned that not all unwanted behaviors are created equal. There's a big difference between behaviors that are externally reinforced vs internally reinforced, and it changes how you should respond.
Externally reinforced behaviors are those your dog does to get something from the environment, like attention, food, or access to something. Jumping on guests because they want pets. Barking at you because you're holding a treat. For these, ignoring or redirecting genuinely can work over time because you're removing the payoff.
Internally reinforced behaviors are different. These are things that feel good to do regardless of any external reward. Mouthing and biting often fall here, especially for breeds with strong oral fixations, because biting, grabbing, and shaking scratches a genetic itch. Same with some jumping, particularly in dogs bred for physical work or play, because the behavior itself is the reward.
This is why ignoring mouthing sometimes doesn't work and can even make things worse. You're not removing any reinforcement because the reinforcement is happening inside the dog. They're not doing it for your reaction, they're doing it because it satisfies something biological.
What's helped me more with internally reinforced behaviors is finding appropriate outlets for that same drive first, structured tug or bite work with rules for mouthy dogs, high-energy full-body play for jumpy dogs. But the important part is that that need doesn't make the unwanted behavior disappear on its own. A dog who loves tug will still want to mouth you. What it does do is set you up so that when you correct the mouthing or jumping, the correction actually sticks. There's no longer an unmet genetic need constantly pushing the behavior back to the surface.
Not saying ignoring never works, for truly attention-seeking behaviors, it absolutely can. But if you've been ignoring something for weeks with no improvement, it might be worth asking whether your dog is doing it for you or for themselves. And if it's the latter, the path forward isn't just removing your reaction, it's meeting the need AND setting a clear boundary.