When someone has been pepper-sprayed or bear-sprayed, there are a few things you can do to help them. The most important step is flushing the area with cold water (avoiding rubbing motions), and if you have it, a non-oil-based soap, such as Dawn dish detergent. Using greasy or oily soaps will further aggravate and prolong the irritation because it traps the capsicum particles close to the skin.
Officially, experts do not recommend flushing affected areas with milk because milk is not sterile. In my personal experience, putting a facecloth over the eyes and affected areas of the person who’s been sprayed and pouring milk over the facecloth has been effective. Think of the process of waterboarding, but coming from a place of compassion. This method ensures the person’s eyes are closed so they’re not getting milk inside their eyes, but they are still getting some relief as the casein in the milk neutralizes the pepper spray on their skin. The best kind of kinds of milk to use is either whole milk or (if you happen to have it!) the very alkaline milk of magnesia, which I know, isn’t technically milk at all.