Effect of Isotonic Saline Nasal Lavages in Improving Symptoms in SARS-CoV-2

I used saline solution both as apothecary bought nasal spray and with a "rhino horn" used with tap water and some sea salt.

tap water may have bio-contaminants in it (like brain-eating amoebas, apparently); use distilled/sterile water

Hmm, good point, though over here in Helsinki tap water is extremely clean. https://www.hsy.fi/en/water-and-sewers/quality-of-drinking-w...

the water here is clean, too, but "clean enough to drink" does not mean "sterile"

Effect of Isotonic Saline Nasal Lavages in Improving Symptoms in SARS-CoV-2 (frontiersin.org)