The Hair of the dog is a good place to start, but if you really want to get rid of that hangover you need to rehydrate. A person not posessing your intellect and charm would assume that this would be best done via drinking wateror gatorade. This approach is wrong in every sense of the word, you simply cannot drink enough fluids to replenish the fluids you lost in metabolizing the alcohol. (Or the amount of fluid you puked onto your shoes, on the fender of some guy's Cadillac, and on you prospective date's outfit.)
The answer is to somehow bypass the mouth and to get fluids directly to the inside of your very dry body. This can be accomplished most easily by the adminstration of 2 to 5 liters of Normal Saline or Lactated Ringers at a wide open rate via a 15gtt/min admin set flowing through a large bore catheter (at least a 14ga.). If you can get your hands on some pure Oxygen then administer 15 lpm via a Non-rebreating mask for about an hour. Now for the coup d' gras, get some vitamin B12 injectable solution and have someone give you a shot. This will eliminate a hangover in about 30 minutes or so.
But...., if you can't scrounge up all of this medical stuff then you could self administer a coffee/canola oil enema. It won't help the hangover, but it should give you something else to think about.
The above information was for entertainment purposes only and should not be follwed by anyone.YMMV