Desperation to win can make you fall for anything but i am sure that it has nothing to do with voodoo or black magic but rather its a matter of chance.
Just to increase the odds of winning and luck but it has no relation. Last time, I've seen those beliefs like wearing 'polka dots' to win which really I find it odd and somehow but I respect their belief. If they are confident with these kinds of belief and don't harm others, I think it is fine on my end. But I don't believe with such thing like that. It isn't all about the chance but you've got to be wise too whenever you play those games that requires thinking.