Product pairing, also known as cocktailing, is very popular in the beauty world, especially with hair care products. Very few people use a single brand, let alone a brand's entire collection, as their Holy Grail. When it comes to trying new products or switching regimens (e.g. CG Method) there are a lot of things to take into account in regards to expectations and product performance. Recently, TheBlondieDream posed a question in Curly Q&A about switching brands.

Question

Since I use some decent products I found here in Italy (not all CG approved) I would like to know if I should use a clarifying shampoo before getting started with the SheaMoisture products to get rid of the dimeticone? My Bf has a bottle of Head and Shoulders Silk and Smooth and I was thinking of it but I saw it also has dimethicone.

Answer

Cleansing

When you are switching brands, I think cleansing should always be the first step. Can you properly judge how effective a product is when it is paired with another brand? You shared that your conditioner and leave-in conditioner are formulated with dimethicone. Well, if you are layering a styler that does not contain silicones (e.g. SheaMoisture Coconut & Hibiscus Curl Enhancing Smoothie) over your current leave-in conditioner, then which is to blame for product buildup or dryness? The leave-in conditioner is probably the culprit.

When you are switching brands, I think cleansing should always be the first step.
Cleansing is important when switching to a new brand, and a co-wash may not be effective enough, especially one that contains non-water soluble silicones.

Product Pairing/Product Cocktail

Hair care brands rarely release solitary products, as they usually launch collections. I am not sure how the cosmetic chemist do it, but they are the masterminds behind product formulation. They intentionally formulate products that are to be paired and build on other products within a specific line or brand. pH balance plays a huge role but I am sure there are other determinants. Unless you are an expert in product formulation, I do not think it is fair to give a final verdict about a product's performance when paired with other products (e.g. moisturizers with stylers) unless you are using products within the same collection. So often curlies will talk about a styler producing flakes or white residue, but what if that styler was not formulated for that moisturizer or leave-in conditioner?  

Following Instructions

Read the instructions. Some conditioners explicitly state that the hair needs to be cleansed before application or it needs 15 minutes with heat to properly process. It would not be fair to judge the effectiveness of a deep conditioner that was only left on for 30 seconds or blame a deep conditioner for leaving residue when the instructions explicitly state that it needs to be rinsed but you used it as a moisturizer or styler.

I am not anti-product pairing, but you have to acknowledge that it may not be the product itself that does not perform well on your hair; it just may not perform well because you did not follow instructions or paired it with products it was not designed to pair with. 

Have you ever used a product that only played well with other products in its line/collection?