Generally its not a problem. If you are candling them once a week and tossing the quitters to the pigs. Give any that make it the full 3 weeks without hatching the sniff test first (you can smell a rotten egg) or a very, very, gentle shake to feel if they are liquidy inside. Those that are,
should be carefully placed in a bucket and taken out to the back forty to be thrown against a tree/rock. The reason for this is that they make a satisfying explosion when they hit. (kid entertainment) They also make one heck of a stink which is why you do this at the back forty. You can give rotters to the pigs who will pop and leave them, but than the whole area will stink something awful. Thirty stinkers would make a skunk blush. Than, there is the compost heap as mentioned.