I think you are all missing the point,
The original poster should start drinking coffee as soon as possible. Preferably around his parents. Just kidding. The Caffeine doesn't do anything to speed up growth, but coffee is full of Nitrogen.
I promise, though. Fertilizing is no difficult or dangerous if you follow the instructions of others. Just dilute the dose. Not risky. If you can divide by two or four, then you can fertilize
I have thought about using coffee... But fertilizer is more standardized. A pot of coffee that I make is made with five heaping scoops of grounds. Another person might make coffee half that strong... So should I dilute mine by four or two or keep it straight? Tats rhetorical since I don't use coffee, but something to consider. But I doubt it matters anyway... It's just seed water.