Washing out dishes: An odd sign of bulimia

As a bulimic I am often ashamed of what I eat. I am seen as a very selective eater - something that I've developed because of my history of anorexia. So having people see evidence of bowls of mac n' cheese, full-fat ice cream, and other unhealthy things bothers me. Not only is there an immense amount of shame it also proves, very obviously, that I have binged.

Other bulimics may wash their own dishes; since I want to "prove" I'm eating to my family (I restrict around my family and binge/purge in private) I simply wash out the food evidence - the sticky cheese, the puddle of ice cream, the frosting off a spoon, etc. I'm left with a washed plate/bowl/utensil and I put it in the sink. Since the tap is often on and off (handwashing) the lack of food left overs is easily explained.