Place the wheat crisps into a blender. Cover and blend until finely crushed. Place the crumbs onto a plate. Beat the egg white and water a shallow dish with a fork or whisk. Dip the chicken into the egg mixture. Coat the chicken with the crumbs.
Spray a 12-inch skillet with the cooking spray and heat over medium heat for 1 minute. Add the chicken and cook for 15 minutes or until the chicken is well browned on both sides and cooked through. Serve with the salsa and sour cream, if desired.