I'm not sure what would be considered clean, but you could buy the ranch powder ( comes in bottles or packets ) and mix it with plain lower fat regular or greek yogurt instead of following their recipe. That can save you some calories. That's the only way I know to get close to a real ranch flavor and avoid all the mayo.

I have been mixing my Ranch powder with plain greek yogurt but recently have tried to find a recipe for homemade mix so I can cut out the preservatives, non-clumping agents, salt, and msg. I haven't found one that I love yet, but I know it's out there. In the mean time I have tried a couple that make me feel better about the amount of ranch I can balance on a celery stick.

You could also use the mayo made with olive oil and that is much better option than reg. mayo. In the diet i am doing from the doc they allow me to have in moderation of that mayo with olive oil. and you mix it with skim milk and that to make hiddenvalley ranch

This is 18 calories for 2 Tablespoons - I haven't tried it yet, but it's on my list to make next! I hope it's good!

Homemade Greek Yogurt Ranch Dressing
Author: Show Me the Yummy
Recipe type: Dressing Prep time: 10 mins Total time: 10 mins Serves: 11⁄2 cups
Homemade Greek Yogurt Ranch Dressing - easy, healthy, and delicious! 200 calories for the ENTIRE recipe!

Ingredients:
1 tablespoon dried parsley
2 teaspoons garlic powder
2 teaspoons onion powder
1⁄4 teaspoons ground black pepper 1 teaspoon salt
1 tablespoon fresh chives
1 cup non fat plain greek yogurt 1⁄3 cup buttermilk
1 teaspoon Dijon mustard
1 teaspoon lemon juice

Instructions:
1. Place the spices (dried parsley - fresh chives) into a food processor and pulse a few times, until the spices have been ground up a bit.
2. Scrape down the sides.
3. Place the remaining ingredients - greek yogurt, buttermilk, Dijon, and lemon juice - into the food processor and
pulse until the ingredients have been fully incorporated.
4. Scrape down the sides, if needed, and pulse again.
5. Transfer into a sealable container (like a mason jar) and place in the fridge until you're ready to use it!

Notes:
** Nutrition information is for the WHOLE recipe! Eat up!
*** This is a pretty thin dressing, if you like thicker dressings, slowly add in the buttermilk, until the consistency you prefer is reached!
Nutrition Information
Calories: 206 Fat: 1.1 Saturated fat: .5 Protein: 16.7

Tried this recipe from Skinnytaste a few times. I always forget how much I like it until I make it again. http://www.skinnytaste.com/2011/09/low-fat-buttermilk-ranch-dressing.html