All skin types can benefit from exfoliating but those who have oily or blemish-prone skin, or clogged pores can benefit significantly. Blackheads or blemishes can occur if the oil gland produces too much sebum. Sebum is a soft wax that should liquefy when it reaches the surface of the pore, spreading a thin, imperceptible protective layer over the skin. But when too much sebum is produced, the liquefying process can get backed up. Add to that problem a tendency for skin cells that should be naturally sloughing off to instead fall inside the pore lining and get stuck. The more skin cells that build up in the oil gland, the more oil will be held back from flowing easily out of the pore (the pore is the exit path for oil), and the result can be a blackhead or, when the right bacteria that cause inflammation are present, an acne lesion.
Often with oily skin, cells that should be shedding on a regular, daily basis are being held back. One thing that keeps cells from sloughing off is that self-same oil (sebum). The oil works as an adhesive, preventing the shedding skin cells from going where they are supposed to go—off the face. One way to keep pores from getting clogged is to help skin cells shed as freely as possible so they don’t get trapped inside the pore. The more you keep skin cells exfoliating in a normal manner, the less cell debris can fill up the pore.
Another issue for oily skin with clogged pores is that the oil gland itself has a skin lining (epithelial lining). For some reason, this lining inside the pore can become thickened or misshapen and choke off and block the flow of oil out of the pore. Using exfoliants that can exfoliate the lining of the pore, thus restoring a more natural shape, can encourage a normal flow of oil and eliminate clogged pores.