I recently got the worst adult acne on my back and face I have ever had.  I apply this with a Q-Tip on the affected areas after either I tone with pure rubbing alcohol or witch hazel.  (Usually back, chest and cheeks), wait 15 minutes naked then put on my pajamas and go to bed.  The smell is pretty bad and my room has this smell lingering but who cares!  This really dries out active pimples and "opens up" under the skin cysts. I have noticed even when I use a little bit on a pimple not only will that pimple go down, but the surrounding areas will break out less often.  Maybe it's killing the bacteria that spreads and causes more acne?  Either way it's DEFINITELY not a cure-all or even an overnight cure but it is consistently effective in reducing bumps and pimples and when you're dealing with an all out attack, this helps tremendously.