The article you link to specifically mentions that people who ask for counseling are of three kinds: those who only need one session, those who are beyond help (and who really should file for bancrupcy), and those who actually participate in long-term counseling. The "rather low" success rate is only counted for the latter category. It even ignores the first category.
Which as I see it means that... Your friend has a chance to get into the "beyond help" category if he doesn't get help ASAP. Of course counseling will require a serious effort from him to change his money management patterns, but I don't see how counseling could hurt.
Incurring debt is easy - just go sign for a loan. Managing debt is much harder, and anything which requires effort has some dropout rate. So those claims that it just "doesn't work" should not by themselves make you think counseling is useless.