Both online and offline method of gambling has their advantages and disadvantages. When it is about curing someone who is addicted you can see it as this;
The solution you have mentioned won't work. If the person is the one who makes money for their family, usually they don't care what others say. Because they are the person who makes money and they are the person who decides where to spend it. The only solution to refrain from gambling is counseling.
As I said in my other posts, they have to be responsible to their family. They have to think about their family members. They have to do money management. Even if they gamble, they have to put a limit on it. If someone loses his entire salary by gambling, then they will suffer for the entire month. The person who is responsible has to think about it.