Homemade Ranch Dressing

This recipe is from Sue Sanders, it is the best Ranch Salad dressing recipe that I have ever tasted.
Ingredients

1 quart mayonnaise
1 quart buttermilk
2 tsp onion salt
2 tsp accent
1/2 tsp garlic powder
3/4 tsp pepper
2 tsp salt
2 tsp parsley flakes
Directions

Just mix all of the ingredients together and chill for at least an hour before serving. Will save in the refrigerator for weeks, if it lasts that long.