Here's a good article from Sistaslick on clarifying. #2 is the main reason I clarify so often. Still trying to find the chelating info...
Do I Need to Use a Clarifying Shampoo?
By Audrey Davis-Sivasothy
Clarifying shampoos get a bad reputation for their tendency to dry out the hair. But really, they are just doing their job—lifting stubborn styling and finishing products from the hair! So when should you use a clarifying shampoo?
Most people can benefit from using a clarifying shampoo occasionally. Clarifying shampoos are formulated with a higher surfactant-to-water ratio to deep cleanse the hair. They are designed to lift stubborn residue, products and dirt. Because the focus is on cleaning, they often contain very few emollients and conditioning oils to balance them out. Clarifying shampoos are usually clear for this reason. Any shampoo can clarify the hair if the surfactant ratio in the formula is sufficient.
You need to use a clarifying shampoo if any of the following scenarios apply to you:
1. Your hair is really oily.
If your hair is naturally oily, then clarifying will be useful to you. It will keep your hair fresh, clean and oil-free and won't leave you feeling weighed down. Because clarifying shampoos can be drying, always follow them with a light conditioner to soften the hair.
2. You've been using lots of oils, heavy conditioners and finishing products.
Products that are not water-soluble, like heavy oils and silicone-based ingredients that are found in everyday conditioners, moisturizers, mousses, gels, serums and hairsprays, can build up on the hair and cause it to feel limp, icky and lifeless. A regular moisturizing shampoo won't be able to lift these stubborn ingredients. You'll need to use a clarifying shampoo to remedy this build-up.
3. You've been swimming.
Chlorine and salt residue from swimming in pools or hanging out at the beach can really damage your hair if they are not removed promptly. Combine them with sun, and the damage is multiplied. A clarifying shampoo will help you get your hair back to normal after chlorine exposure and will prevent unnecessary damage to the hair.
4. None of your products are working.
When silicone and oils from your hair products build up on your hair, they may cause your favorite shampoos, conditioners and other products to "stop working." Your shampoo might not lather properly, and your hair might feel weighed down after deep conditioning. The problem is simply product build-up. Whenever products you know are good just stop working, don't toss them out. Clarify your hair to remove the build-up.
5. It's been a month since you've last used a clarifying shampoo.
Clarifying your hair can be done as a monthly refresher, and it will give your hair a fresh clean slate for products each month. I've found that after about a month, my hair begins to get a coated, weighed down feeling. Clarifying at least once a month can remedy this. If you use oily or sticky products like serums, regular oils, gels and heavy pomades frequently throughout the week, then you may find that clarifying weekly is a better option. If your hair is naturally oily, then daily clarifying can be beneficial.
6. You are preparing to chemically treat the hair.
Clarifying helps color and relaxer services take better, since it frees the hair of build-up that would normally block the chemicals from penetrating the cuticle effectively. For those with mineral build-up in addition to product build-up, a chelating shampoo may be required to prepare the hair to receive an even chemical service.
Any shampoo can gently clarify the hair if the surfactant ratio in the formula is sufficient.
Sources:
Claude Bouillion & John Wilkinson, The Science of Hair Care, 2nd ed. (Taylor & Francis,1995).
but ORS creamy aloe is a chelating shampoo if I recall correctly ... Lemme double check BRB
It's the shampoo that comes with the box relaxer to neutralize and it's the only time I use it because regular use dries my scalp out.
Google will clear up the confusion.
