I would not use Russian casinos. First of all, I think if I gamble on Russian casinos and lose, then at some point I indirectly support the Russia against the Ukraine because the profit that casino makes goes into Russians budget and funds their soldiers.
Look on a situation from different angle. Try not to lose, but instead make Russian gambling platform go bankrupt. With it, you will reduce amount of tax paid and reduce war funding. How do you like that ? Would you support the movement aimed to bankrupt Russian gabling platforms? Or lets hire Ocean and his friends to rob their safes?
You see, all these boycotts, sanctions, rallies, bans or leaving Russian market does not work so far. This situations between Russia and Ukraine must be settled on a different level.
The opinion you give is another point of view that should also be considered, I know that the war has left Ukraine very badly, but I think that the only one to blame for that is Putin, not his people, we all know that Russia with its rulers, Russia , even the USA itself are not white doves, for a long time there have been very intrinsic interests and that they do not say because of the "diplomacy" that must be kept among themselves, it is something normal, for me this is a geopolitical problem and that the truth it will end when the strongest wins, unfortunately I see it that way, and the rulers no longer care about human losses, be they soldiers or innocent people, to stop this problem I think the solution is far from doing a massive ban on Russian platforms, I think attacking them generates more hate.