I'm sorry, if you're serious, this is the most entitled and egotistical suggestion I've ever read in my life, it's kind of shocking. The best way to spend $20K charitably is to bill oneself $200/hr and spend 100 hours sharing one's massive brain with homeless people by giving them... a talking? (While, again, billing $200/hour for it.)
Then spend that well-earned money on hookers and blow? You've made a difference?
I don't think it's helpful to others to go clubbing, in fact it's not an activity I'd do myself if I had that much money (nor would I waste money on a car).
My point is that the $20k can't help someone as much as you can personally.
So someone who is homeless and forced to beg or commit petty theft in order to eat would appreciate a chat more than $20k? You should try that and mention you're paying yourself $200 an hour because you think that's better for them.
Then spend that well-earned money on hookers and blow? You've made a difference?
Honestly... words fail me.