YSK: Using dairy milk after being tear gassed or pepper sprayed doesn't provide more relief and has slightly increased infection risk. Use water or saline instead
Generally medical professionals do not vouch for using milk for tear gas despite it often being touted. The research seems to suggest they are largely the same in providing relief
Sources to back this up
That means bacteria can contaminate the milk and potentially cause infection if applied to eyes or skin wounds. Jordt says it’s better to use water or saline solutions to wash out eyes after a tear-gas attack
In this study, there was no significant difference in pain relief provided by five different treatment regimens. [Water vs milk vs 3 other solutions] Time after exposure appeared to be the best predictor for decrease in pain.
Wouldn't beer have less infection risk because of the alcohol? Disclaimer, I didn't read any of the articles and have no expertise beyond drinking beer.
Nitpicking: the fermentation is done by a fungus, specifically a yeast strain. The fermentation process stops when you introduce oxygen, aka open the fermentation tank, or when the sugar in the wort is depleted. The yeast then just becomes inactive and you can potentially restart the fermentation at home by putting sugar in the beer and sealing it airtight. Most commercial beers remove the yeast through filtering or pasteurizing or both tho, so that would probably only work for craft beer. And it would make the result taste terrible I assume.
Some bacteria do not tolerate alcohol at all and will die from beer, but generally beer is not a disinfectant. Vodka isn't either by the way, still too low levels of alcohol. But it works better than beer.
Beer doesn't have a high enough alcohol volume level to be a disinfectant (recommended is 70+% ethanol, beer has 4-5%), just high enough to get drunk after the fermenting process comes to a halt when the sugar in the wort is sufficiently depleted.