Just as with people, apparently dogs have a genetic predisposition for bitter and some like it and some don't. Trying to dissuade a puppy from chewing on everything in sight, including the older dog, we pulled out the previously unused spray bottle of Bitter Apple. Unlike the other dog who considered it candy, she fell over backwards to get away from the gross taste. If you want this to work, and you want to reinforce undesirable behavior, you need to reapply nearly every day. It might not work for one of your dogs, but consider trying this with new puppies.

Pros: One dog dislikes bitter tastes, Doesn't stain

Cons: One dog loves bitter tastes, Requires frequent reapplication