Question: Given that the virus is transmitted through the respiratory system, should we be doing nasal irrigation (Neti Pot) more often?  

Answer: Interesting question!  So far (considering limited direct evidence), data indicate that yes, nasal irrigation is beneficial, especially to reduce COVID symptom duration.  Nasal irrigation has been shown to reduce symptoms and have therapeutic effects for all sorts of ailments.  The practice stems from India, where it has been recommended by Yogic texts and used for centuries.  I was curious to read a few studies and research notes specifically about nasal irrigation and coronavirus.  And here’s a brief synthesis of what I found:

• Nasal irrigation can reduce symptom duration and transmission within household contacts of the common cold. This paper published last year in Nature, “A pilot, open labelled, randomised controlled trial of hypertonic saline nasal irrigation and gargling for the common cold,” published results of a small randomized control trial comparing hypertonic saline nasal irrigation and gargling vs standard care on healthy adults within 48 hours of upper respiratory tract infection.  Researchers found “duration of illness was lower by 1.9 days (p = 0.01), over-the-counter medications (OTCM) use by 36% (p = 0.004), transmission within household contacts by 35% (p = 0.006) and viral shedding by ≥0.5 log10/day (p = 0.04).”   
• Nasal irrigation likely decreases viral burden through physical removal of viral particles.  This viewpoint published by JAMA Otolaryngology in July, “Benefits and Safety of Nasal Saline Irrigations in a Pandemic—Washing COVID-19 Away” suggests that nasal irrigation is likely to reduce viral load and recommends, “Given the safety profile of these therapies, HS nasal irrigations should be encouraged for patients and health care workers especially.”
• Nasal irrigation seems to reduce symptom duration in COVID-19 patients. This interim analysis of a randomized control trial undertaken at Vanderbilt University, published in the   International Forum of Allergy & Rhinology found  “The effect of nasal irrigation on symptom resolution was substantial, with nasal congestion and headache resolving a median of 7 to 9 days earlier in the intervention groups.”

Two caveats: 1) Nasal irrigation materials and their surrounding area could potentially become contaminated and serve as a source of future infection; 2) FDA considers nasal irrigation systems safe, but also warns that use of tap water for nasal irrigation and/or improper cleaning nasal irrigation devices can results in serious infection. Please practice good hygiene!  CDC provides guidance for safe use of nasal irrigation devices here.

Image 1. Nasal irrigation in practice (from FDA)