the crystals are no good. i have never incubated eggs but i can tell you that they are super hydroscopic taking in all moisture. those containers work with leopard gecko clutches but i dont see why you cant use them. you just gotta buy a couple. for medium use hatchrite or straight vermiculite...
its a beer brewing steriliser which is completely bio degradable and safe to consume. you can leave the suds on the container and it doesnt harm the flavour of the brew or you(hopefully)...