Can Advantage ever be ineffective in dogs?

Advantage and frontline work, however they do not treat the environment, only your dog. If the dog has had fleas for a while without you noticing, the fleas will likely be all over the house. Even though the fleas on your dog are dying, new ones will keep jumping on and breeding elsewhere in the house. Your best bet is to set off a few flea bombs in the house and then readminister the advantage