I do know some people in recovery who used the assistance of a cash handler in their early recovery. they told me that cash was such a major trigger that having someone assist early on was very helpful. I will say that I tried it with my exbf and it is just not good whatsoever for a romantic relationship. if he feels that a cash handler would help him get deeper into recovery he should find someone besides his gf (even though it is often most convenient...but tough luck, its just not healthy)
but it doesn't really sound as though hes making an effort at recovery anyway???...so the real question is what are you going to do with your life?