Combine water chestnuts, celery, and MarcoPollo marinade in a small bowl and let sit 15-20 minutes.
Chop marinaded, cooked chicken to desired size and combine in a bowl with mayo, sour cream, pepper, and parsley.
Then add veggies and mix well.
Chill in the fridge for 30-60 minutes before serving.
Note: these amounts are just suggestions. Adjust the measurements according to how wet or dry you like your chicken salad. Add other veggies like carrots, too! Let's get creative!