Those countries first of all are few compared to countries that allow gambling and only based on that there is no need to bribe anyone.In Europe where I am located I can access many of the reputable casinos and most of them have a license to operate in a market which I call gambler's friendly as we are huge gamblers in Europe in almost every single country.
I know that many people use VPN-s although they are doing so at their own risk because if caught most casinos won't let them as it is against their terms and services and as such VPN is not a recommended solution.