When you use the coconut oil as the article suggests, your dog will lick some of it off of his or her skin. The coconut oil that is ingested is not harmful, and probably does a lot of good. It is not necessary to give more in the food, and if you give too much your dog will have loose stools/diarrhea.
ACV may or may not be helpful in the water. There is no proof of this. I prefer to use it topically, as described in the article, and have seen excellent results.If you want to use it in the water also it does not hurt, as long as you do not add too much. (Only add about a teaspoon in a bowl of water. Some dogs do not like the taste, so if your dog will not drink you have to provide another water source. Please do not let your dog become dehydrated.)