Can I give my 5 week old nasal spray?

My five week old is very congested. Before I realized there was a difference between saline nasal spray and regular nasal spray I gave her a few drops of the regular kind. It worked perfectly. My little one could breath, eat, and sleep easily. However, I was then advised from then on out to use saline drops. I tried this and they did not work at all. She was just as congested and wouldn't eat or sleep. It is breaking my heart to see her like this. All of the sources I have found do in fact say to use saline drops, however I cannot find any sources saying not to use regular nasal drops. Any one have and information or advice for me?