A certain English-speaking doctor in Tokyo prescribed me Differin when my acne is hormonal acne, and now it's no longer hormonal. I should've known then. Now I regret it so much 
Another advice for teens with acne: those days will pass. The day when you'll be acne-free will come as long as you follow these rules:
1) Do not ever use cleansers. Water will do. If you begin introducing chemicals to your skin, it will start depend on it. The human body is capable to keep your face clear. Believe in God.
2) Rule 1 would work only if you stop touching your face and simply stop obsessing. Don't look at the mirror too much, don't start picking. I, for one, has developed that habit throughout the years and now I really can not stop. But I'm trying hard.
3) Stay away from the sun. Really. Wear hats. Umbrellas, whatever. Now that I think of it, my skin problems started when I spent too much time under the sun.
4) Keep your pillowcase clean.
I know two people who never use cleansers and their skin is baby smooth. My mom never used cleansers when she was young, and she never had acne until she got pregnant. It really depends on your genes, I think.
Nothing wrong with cleansers as long as you buy smart and research products and ingredients. If I washed my face with water only it would be one pimply oily mess. It works for some people because plenty of people have perfect skin genetically to begin with whether they do or do not use skin products. Chemical or natural, cleansers can greatly benefit your skin. People tend to come up with this sort of mumbo jumbo when the traditional methods fail. But just because what you tried haven't worked doesn't mean nothing will, nor that these things are bad for everyone.