Disinfectants have gotten less painful over time, but you may be old enough (or, younger but less fortunate in the compassion of those who have tended your injuries) to have experienced having genuine iodine or hydrogen peroxide swabbed over your abrasions as “first aid” at some point in your life. You might say it stings a bit.
This picture comes (judging by various hints around the web) from one of those old “nudist lifestyle” magazines. And when one is enjoying an outdoor life of sunshine and exercise sans protective clothing, abrasions do happen:
Judging by facial expressions, this particular bit of first aid stings more than just a bit.