It is very difficult to give advice, since you are the one that needs to make the ultimate decision. Crack addicts are difficult to treat and very few recover. Most rehab centres are not aware of the biochemical underpinnings of drug addiction. You might want to read:

Drug Addiction is a Nutritional Disorder at:

http://www.hypoglycemia.asn.au/articles/drug_addictions_nutritional_disorder....


But your friend has to be very motivated to do the course.

I can only advise you to be very careful, because drug addicts can be very destructive of other personalities as well.