I used to have really oily skin. I remember someone told me that their dermatologist said it's unnecessary to wash your body with soap everyday and that skin usually gets clean enough from the water and run down of shampoo and/or soap on the face. So a couple years ago I tried this and stopped washing every nook and cranny on my body with soap everyday (and now I only do when it's a must like after having been working in dirt or whatever, which is rare, easily less than once every couple months). Worked wonders for my body. I no longer have to deal with dryness immediately after washing or oiliness after the dryness wears off as I did when I was younger. And recently I stopped washing my face with soap and replaced it with extra virgin olive oil. My face is now no longer oily. And it's even dry at times after shaving and I can use lotion without getting oily again, whereas my face used to be quite oily most of the time (minus the dryness immediately after washing). And no, I don't smell like a salad, nor does my face still feel dirty. Moral of the story, soap isn't very good for the skin.
If I'm not mistaken, part of the science behind this is that if you don't wash with oil removing stuffs (ie. soap) as much, your body learns to stop making as much oil, solving the problem and giving you all around better skin in the process.