@gitasanjeevani When I think about ignoring so a behavior goes extinct, I think about seconds or mayyyyybe minutes, not hours. Ideally you want the barking behavior to quickly die out so you can reward a different quieter behavior. If it won't die out in a reasonable amount of time then ignoring might not be the best option.
If yours keeps going for literally an hour, I would bet there's something going on more than attention seeking. Excitement, stress, boredom, over-arousal, etc and the barking is a coping mechanism.
Have you considered adding mental enrichment (puzzles, training) to tire out his brain? Or calming training (mat/settle training, capturing calmness, relaxation protocol) to construct calmer behaviors? Or management (crating, other confinement, preemptive stuffed kongs, white noise, closed blinds) to prevent the worst of it? Or giving him different coping mechanisms for frustration/stress/boredom/whatever?
Physical exercise doesn't always calm dogs down...sometimes it actually amps them up even more.