Just because we call something a reinforcer, it may or may not actually reinforce the subject. For example, if we want to reinforce a teenager to clean his room, get all A's, and meet curfew, we have to find something this teenager wants- such as an iPhone. If we want to reinforce a rat to do face cleaning behaviors, an iPhone probably would not hold the same strength of reinforcement as it did for the teenager.
So think about this- a parent insists that nothing works to house train their dog. One of the first things we need to ask is "what is your reinforcer?" Sometimes it is nothing! Maybe the treat is not that yummy to the dog. Remember, conditioning is one of the most basic psychological process of learning. It will work. It just needs to involve the proper reinforcer.