6 month old has awful cold any extra suggestions?

I took my 6 month old to the doctor 3 days ago because he had a fever and was extremely congested they checked him out took blood to check his white blood cell count(blood work was fine) and tested him for some viral infection called rsv which came back negative. The doctor said he just had a cold and it has to run his course. Fever is gone but hes still extremely congested. I've been giving him baby saline nasal spray, suctioning his nose, and using a humidifier. He's still very congested though so I was hoping maybe someother Moms/Dads had any other suggestions or ideas that would work. Any extra help would be great!