the best way to quit gambling is not visiting the place or browsing to the sites and its better you stay away from any of device you use to connect internet and doing another activity before you can start new things. i think it will works if you have a friends that is beside you when you start new things so you don't thinking about playing gambling and then after you can calm down your minds from gambling, you can go to trading sites and register and start to trading. maybe this is not work but at least you can try to quit from gambling and start new habit.
What you arr saying is that he must be indoors at all times depending on where he is and he must be disconnected from the internet all because he has to start gambling, I rather think he needs to talk about his gambling problems with other gamblers and get over it before he starts trading which in my opinion is an educated guess which is effectively the same as gambling.
Even how could he even start the trading without access to the internet and so i think he doesn't need to entirely stay away from gambling or the internet like you are saying but face the problem head-on by engaging friends and if possible a psychologist and even former gamblers