As a vet, we have to specify withdrawal periods for drugs in farm animals. If not licensed for chickens (most drugs!) then the standard withdrawal period is 7 days. This means that the amount of drug left in eggs after 7 days has not been tested, but is thought to be sufficiently low to not be a problem for people. It is to a certain extent your own risk to eat eggs after this date, but likely to be safe. If eggs are discarded for 7 days then you are doing everything right and no reason you cant give them away or sell them after that point.
Hope that helps