Bring a saucepan of water to a boil. Add salt, bay leaves, white pepper, onion powder, and garlic powder.
Add chicken breasts, reduce to a simmer, and cook for 20 minutes.
Remove from heat and let the chicken cool in the water while you prepare the salad mixture.
In a large bowl, combine Greek yogurt, sour cream, dill pickle liquid, everything dill seasoning, mustard seed powder, and a pinch of salt. Stir together.
Add chopped scallions, diced dill pickles, and parsley to the bowl. Mix to combine.
Shred the cooled chicken with two forks and add it to the bowl.
Fold everything together until chicken is evenly coated.
Taste and adjust salt as needed. Serve on bread, in a wrap, over greens, or with crackers.