This is the case that you need to have unlimited money to try this strategies which actually is not really possible unless in starting itself if you win it that it is your luck. So practically speaking play for fun and if won enjoy the money and move out and not to become so greedy that even the winning amount is lost.
What many gamblers do not realize is that even an infinite amount of money is not going to be enough to make the martingale system effective, casinos have table limits precisely for that reason, if you use a martingale system you will need to increase your bet more and more and eventually you are going to hit the table limit that is established by the casino and once you do that you will be unable to recover the money that you have lost with your martingale system.
Casino owners are not dumb, they know their games and they know the strategies that people could use to try to make money in the casino and probably the most tried strategy is martingale so they have created ways to protect themselves from people that have big amounts of money.