Water is a great solvent. It’s neutral and doesn’t provide any strong positive or negative effects. It just helps components to mix better and to transport active components.
Cetearyl Alcohol is used mostly for formulation purposes. It’s a very good emulsifier and emulsion stabilizer. It helps the ingredients mix better and it makes the product spread on your skin evenly. It also makes the product thicker. It doesn’t belong to harmful alcohols and it will not dry your skin.
Propanediol is a good solvent, emollient and humectant. It helps to moisturize the skin and prevent moisture loss. In haircare products, it conditions hair and improves absorption of the product.
Stearyl Alcohol creates a barrier on the skin's surface lowering the evaporation of water and making it hydrated for a longer time. This barrier helps the skin to recover after deep cleansing. It also makes the skin look smooth. Though it belongs to alcohols, it's a fatty alcohol and it doesn't make your skin dry.