Have you ever used hair care products that didn't live up to your expectations? Did you have a hard time wet combing your hair, and dry coming wasn't much better? Did it leave your hair dull, dry, flyaway, or frizzy? Well, the reason for that is an electrical one.
Everything has an electrical 'charge', it's either positive (+), neutral (N), or negative (-). Positive (+) attracts negative (-), negative (-) attracts positive (+), positive (+) and positive (+) or negative (-) and negative (-) repel each other (like the same two end of a magnet). Shampoos and conditioners have to be formulated with this science in mind.
SHAMPOO
Hair is negatively (-) charged. Therefore, you want a shampoo with negative (-) or neutral (N) charged ingredients. The 'soap' in the shampoo works by surrounding the dirt, oil, sweat, and styling products, and the negative (-) or neutral (N) charges of the hair and ingredients, that repel each other, allow the water to rinse them off, leaving your hair squeaky clean, the cuticle lifted, and ready for conditioner. Once your hair is clean, you need a conditioner that's positively (+) charged so those ingredients will stick to your negatively(-) charged hair.
Squeaky clean, "I've been told that I should not 'strip' the oil from my hair"...marketing , marketing, marketing! First of all, your hair doesn't secrete any oil, the scalp does (along with sweat), it's called 'sebum', and when you comb or brush your hair you distribute that oil and sweat throughout it. Then dirt sticks to the oil and sweat, and your hair get 'dirty'.
You want to strip-off the scalp oil/sweat, dirt, and styling products, when they're all cleaned off your hair will be 'squeaky' clean. If your hair is not squeaky clean, it's NOT CLEAN! What do you think 'clarifying' shampoo does? It strips-off all the things that your 'regular' shampoo leaves on your hair.
The reason shampoo companies sell clarifying shampoos is because their 'regular' shampoos don't work properly (and they know it), and that's because they put ingredients, like oils and conditioners in them that stick to your hair, and prevent it from getting completely clean.
Everyones hair is made of exactly the things. But the shampoo companies have indoctrinated people to think that there are different 'types' of hair. While it's true that the 'condition' of hair can differ from person to person (oily, normal, dry, very dry, etc.), that doesn't mean they all need different shampoos, and those conditions (oily, normal, dry, very dry, etc.) should not be addressed in the conditioning stage anyway.
People only need one shampoo for all hair types, and the only things that should be in it are; water, thickener, surfactant/s (soap), and a preservative, and they need to have a neutral (N) or negative (-) charge, no oils or conditioners.
Another advantage to cleaning your hair properly is that you don't have to wash it as often and that cuts down on damage to your hair.
CONDITIONER
Once you have properly cleaned your hair, you're ready for the conditioner do the heavy lifting. That's where you want all the; anti-static, anti-frizz, repairing, softening, moisturizing, and nourishing ingredients to be.
The ingredients in the conditioner need to have a positive (+) charge so they will stick to the hair. So if the formulator has done a good job, your hair will wet and dry comb like a hot knife through butter, not tangle, not become frizzy during blow drying or humidity, and will be be soft, shinny, full, and manageable.
One conditioner is all every hair type needs as well. People who have thin, oily hair can just use less and rinse out about 95%. People with VERY dry, curly hair will need more and to leave in at least 50%. The conditioner can also be diluted and used as a leave-in product.
I'm a very good formulator and my shampoo and conditioner have the correct charges so they work together to give you the results you're looking for to thoroughly clean and condition your hair.