My definition of an addict is someone who by the power of their own free will cannot control the use of a substance or process. They need a major life change and attitude change to get their lives back in order. for most of us that means we need to get the substance or the process out of our lives, and then work on the underlying issues that caused us to compulsively return over and over to that which was stealing our lives from us.
Now, I know of people who COULD cut back, have a beer with dinner, etc. Those people don't fit my definition of an addict. If they can control their use, then...what's the problem? My problem was that no matter how many times I decided to control my use, I couldn't. When I decided to stop using and deal with my issues...my life started to become liveable.
If your friend is truly an addict, I am afraid he will find out the hard way that his plan isn't going to work. I found it out the hard way, when I screamed my way through an 80 mile ambulance ride to the hospital after having my door kicked down by EMS. Oh..I guess I CAN'T control my using!
I put down alcohol and drugs, I don't see any good reason to take up gambling, especially something as precious as recovery.