Soap de-greases, it will resolve the fatty outer layer of the virus which will kill it. We advise to clean the headcaps with lukewarm water and soap. A shampoo optimized for delicate fabric is advised, for example https://shop.neurospec.com/ivory-electrode-cap-shampoo-750ml# or similar. Use a soft brush to clean and de-grease the inside of the electrode holders.
According to literature, alcohol (ethanol) kills the virus within 30 seconds. The electrodes can be submerged in alcohol without damage (tested for many hours). So, submerging the electrodes for a few minutes in alcohol (minimum 70%) should be the most effective way to prevent Covid-19 infections. In the below video, cleaning instructions are shown with regards to COVID-19.. https://www.youtube.com/watch?v=-CZx3_tbrYM
Washing the headcaps intensively and frequently may affect the elasticity of the fabric (just as with washing normal clothes). On the same way, long and frequent disinfecting with alcohol may also have an effect on the elasticity. The electrode holders and rubber rings will certainly not be affected. Until we know more about the long-term effects on the use of alcohol, we advise to not submerge the headcaps for more than 3 minutes in alcohol and dry the headcaps immediately afterwards. To kill the virus, 30 seconds should be enough anyway.