The secret to meth treatment is to create new lifestyle that can replace the old one. This involves a lot more than simply walking away from the drug and replacing your old friends with new ones (though this is a necessary start for most people in early recovery).
The long term goal in treatment for meth is to create a new life. This means adopting a new lifestyle that does not involve self medicating with drugs, nor does it involve relying on a drug to fuel a “good time” for the person. These might seem like impossible changes to the meth addict at first, but they are definitely reachable goals if they are serious about creating change.
Of course the meth abuser must make a decision just like any other addict who is going to try to overcome an addiction. They must decide that they are done with the drug and that they truly want to change their life on a really deep level. They must be completely defeated by the drug and ready for full surrender. This means that they have to be ready to accept something new as their solution for how to live. They cannot be caught up in trying to control their life or the lives of others. If they are hanging on to the need for control then this is a form of denial and it is unlikely that they will be able to stay clean.
There is not much of a need for detox from meth. There are no life threatening withdrawal symptoms. In fact, there are hardly any physical withdrawal symptoms at all. The detox process is entirely psychological. So those who come off of the drug do not need a medical detox, but they might need rest, nutrition, and a safe environment where they will not be tempted to go use drugs. Residential treatment makes a lot of sense in this case, and meets all of those requirements.
Some people who are recovering from meth addiction choose to use the 12 step program of AA or NA as their solution. This is fine and if it works for them then that it great. Much support can be had at 12 step meetings to help people to learn how to live a clean and sober life. There are other methods with which to recover but 12 step meetings are widespread and basically free, so they are a powerful resource. If you need support then it might be worth checking them out.