The Sally version of Wen is called "Hair One". It's a cleansing conditioner that is supposed to clean and condition your hair in one step without stripping your hair. Supposedly most, if not all, shampoos strip your hair so then you have to follow up with a conditioner to replace the moisture lost and style with oils and serums to reduce frizz. When you use these cleansing conditioners correctly you don't have to use all of the other products. I do use a little Argan Oil because my hair is curly, but it really is not necessary.
It's really important to follow the directions on the bottle. Using more of the product is better, so the "less is more" concept does not apply. Also, the longer you leave it on the better too. The downside is that it takes longer to wash your hair than it does with regular shampoo and conditioner; however, the results for me is so worth it.
In the beginning, I found that my hair got oily faster so I had to cleanse daily, but once my scalp/hair got used to the product (about 3 weeks), I was able to cleanse every other day. I have fine oily hair, so those who have thicker/dryer hair may be able to go even longer than that.
Hope that helps clarify things a bit.