https://www.bioresearchcommunications.com/index.php/brc/article/view/176/159
Conclusion: Administration of 1% PVP-I as mouthwash/gargle, nasal or eye drop is simple, rapid and cost effective in reduction of mortality and morbidity by COVID-19. In this horrible situation, simple use of 1% PVP-I can change the treatment modality of COVID-19 patient and reduce the hospital as well as financial burden of the globe.
And there is this study:
https://pubmed.ncbi.nlm.nih.gov/32936949/
Cmmt: Consult physician before using.
Drug store sells 10% providone iodine solution. To dilute to 1% combine 1 part of this solution to 10 parts water.