I also have mucus dripping down my throat (but never through the nose) every 5-10 minutes that may come from nasopharyngitis - chronic infection in Nasopharynx area.56% of the healthy population also test positive for mild-moderate nasopharyngitis, so this finding is interesting, but not as significant as finding severe nasopharyngitis.
I am now back to using oil-onion juice-honey mixture instead of zinc chloride on Nasopharynx for 4-5 days straight, and unlike the sinusitis version of this treatment that had to be cycled ON/OFF (to not lose effectiveness), this doesn't lose it's effectiveness over time if used without ON/OFF cycle.
Before I had this major improvement in symptoms, I thought that somehow sinusitis was causing the mucus dripping, but I do not qualify for chronic sinusitis diagnosis, because my nasal cavities aren't blocked according to MRI/CT scan and as stated by several good Drs. I only have mild mucus congestion area in one of maxillary cavities (according to CT scan) that I think may come from inflammation in Nasopharynx area.In short, I used this with oil-onion juice-honey mixture instead of zinc chloride and it put me into near remission after the first use by removing chronic fatigue and PEM, but these symptoms returned after 18 hours and it didn't work after second application.
I couldn't find information on zinc or ZnCl2 antibacterial properties, but maybe I wasn't looking in the right place.That's a reasonable theory, but remember that zinc is a good topical antiviral and antibacterial, so as well as being anti-inflammatory, it may also inhibit infection.