There is no casual relationship between oily skin and acne. Yes, sebum does indeed accelerate bacteria production, but this can only happen inside a compromised pore where the p. acnes bacteria is present. If the skin is shedding normally and the sebum is allow to flow outwards, acne does not develop. Reducing oil at the external level is rather counterproductive, as in an acne lesion the sebum collects within the pore (as I stated earlier). In the process of actually wiping away this oil, you risk introducing bacteria onto the skin and causing irritation. The only retinoid that actually controls sebum production is Accutane, and this is an oral medication.