I hate airplane lavatories

I love to fly, but I hate the lavatories in airplanes. I always make sure I visit the restroom in the airport before I get on a plane. Those are generally very nice. The problem I faced yesterday though, is that I was on the same plane from 9:55 AM until 3:30 PM. There is no way I can make it that long without visiting the cramped lavatory at the back of the plane. At least I only needed to go once. I kept my Diet Sprite drinks to a minimum and doesn't eating peanuts soak up the liquid anyway?