He just kill all people who are involved in drug. You don't solve problems just to murder all who don't fit you ideally country in his eyes. A country without drugs don't exist it will always be part of the world.
Yes he might be brutal in things like that but still many presidents tried to stop drugs and other lawlessness but none really achieved more than the president of the Philippines right at this moment achieved. He is a president who truly loves his people and wants to change this corrupt nation.