Martingale strategy can be used when playing Video Poker. I'm doing it from time to time, and it's fun. You should try it. As it is always with purely luck based games, there's no guarantee that you will not lose your entire balance following this strategy, but if you are ready to stop in time, or your entire balance is not that big, try it, starting from the lowest bet possible, of course.
Martingale is a guaranteed winning strategy only under two small conditions: 1 - there are no bet limits, 2 - you have an unlimited amount of money.
- Using martingale is also sometimes just luck. Because even if your odds are small, if you are lucky the day you play, for sure you will win.
Now, if you are unlucky, I think that's where the player must have a big fund so that he doesn't lose or else his money will just disappear in this way.