As far as using vinegar for our pets, I know that adding a few drops of apple cider vinegar to the dogs drinking water can help keep the fleas from biting, it will eventually go into the blood stream and fleas hate the taste of vinegar. Remember, only a few drops in a large container of fresh cold water.
The best home remedy for flea control I have found is the one I published using essential oils. I think this would be especailly good for your dog because you mentioned the hair falling out. I'd guess your dog developed a skin allergy to flea bites. The essential oils would not only chase the fleas they would also help heal the skin condition and make the dogs coat shiney and healthy. It also makes the pet smell good.
You can find the recipe for flea control if you go to Natu;ral Pest Control, press the button "DIY Pest Control" and look for the link for Natural Flea Control.