Well it is true that there is no antidote for caffeine, just as there is not one for chocolate or antifreeze poison. But yes there are treatments that are given to contain and control the situation so it is not as simple as your dog gets it your dog dies. Every animal has varying levels of sensitivity to theobromine.
The key here is always the amount, with the exception of antifreeze because it takes only a small amount to make them sick. If your dog has a few sips of your coffee or even drinks half a mug will all be okay....yeah probably so and there is not enough caffeine in it to make them get a coffee buzz, maybe a little soft stool if you use milk or cream. Now if your dog knocks over the bag and eats half of the ground stuff or the beans or knocks over a 2 liter bottle and downs it all....well that is another story.
The general treatments:
If your pet has just ate enough that you are worried about it then induce vomiting with hydrogen peroxide. If they dont vomit within 15 minutes, give it again. If that does not work then head to your vet....
There are many medications that are considered supportive treatments (not termed as antidote) and that is......Activated charcoal may be administered every 3-4 hours to reduce the serum in the system, Fluids to help flush any toxic waste in the system, oxygen if needed for rapid breathing, monitor of heart rate, and then there are medications that treat a slow, a fast, or an irregular heart beat, depending on the situation.
You mentioned valium and Insulin is actually the most beneficial treatment for caffeine poisoning....insulin has been shown to be antagonistic to caffeine.
Hope that helps and answers the question!!!!