I've done it both ways because I followed different protcools. But the last time, and only that once time, with the 3/4th cup I threw up some of it in the morning and didn't even have a succesful flush. But I was also way off with the times, I drank it like 8hrs later than I usually do because I fell asleep and drank it when I woke up and slept again. lol
So maybe it wasn't the 3/4th cup that made me sick..it was sleeping 5+ hours, then drinking, then sleeping again..