YES. A humidifier is useful but you must be vigilant at cleaning the machine at least once per week. If your child is stuffy, consider a nasal wash, safe, inexpensive, effective when done correctly.
Clean the air. The first months are troubled by narrow nasal passages & exposure to dust, fragrances, smoke & other irritants.Baby tries to flush these out of the nose with mucus but this often ends as congestion & produces rattling with breathing. The best rx is washing out the nose with saline & suctioning the remainder.Eliminate irritants from babies environment & this will happen less.Humidifiers do little.