How can I decrease the half life of Adderall aside from hydrating?

Even with not taking my last dose after 12pm at dosages as low as 10mg total, I can't fall asleep until 12am/1am.

Any dosage lower than that is basically only half a tab, 5mg, which does nothing.

How can I decrease the half life to get out out of my system faster?

I've heard acidic foods will decrease absorbtion, but I don't want to decrease absorption just speed up the half life.