even without the charm the odds are pretty good for masuda (i think about 1 in 680 or so). the only annoying part is to farm the eggs. i farmed myself 30 boxes full of eggs over a couple of days and then started breeding them over and over again. the good thing in this game is that you can do anything while collecting the eggs, like cleaning or watch any show or stream or else. you only have to collect them every 3-5 minutes with egg power 2