Is drug rehab effective for a person with addiction? And what are the services offered by the center?

It's because I want to enter my brother in a rehab center because of his addiction to cocaine. Also, can somebody give me an idea on how long the treatment process would probably take?

: http://alcoholdrugstreatment.info/is-drug-rehab-effective-for-a-person-with-addiction-and-what-are-the-services-offered-by-the-center