Salicylic peel: Results for salicylic are usually longer because the oil, dirt, and bacteria must make its way to the surface before the skin can begin clearing up, this is why many will experience an initial breakout.
By maintaining an anhydrogenous environment we preserve the lipid solubility of the entire solution. This allows us to greatly lessen the risk of excess irritation because of the nature of the molecules. Salicylic acid is oil soluble, which is great for two reasons. First, the outside layer of you skin is covered in oil, and being oil soluble, the salicylic acid is able to penetrate this outer layer. However under this outermost layer is the dermis, and this layer is made up of mostly water. As you know oil and water don’t mix, and this keeps the salicylic acid from moving down past the outer most levels of the epidermis, and is therefore is much safer than using alcohol/water solvent which would force the salicylic too deeply into the skin, disrupting this natural mechanism.
If you are unsure if the Salicylic peel is effective, after application, you will feel a slight tingling on the skin. This means the peel is starting to penetrate your skin. If you want a stronger response, leave the peel longer on the skin. But remember not to overdo peels. Rinse thoroughly after use.