I have been suffering from seborrheic dermatitis for a few years myself, and I've found that scrubbing the affected area with Head & Shoulders or Nizoral (yes, the shampoo's!) has been consistently effective. If you look at the active ingredients, they're the same as the prescription creams. :)

However, if I don't use the shampoo on my nose for a couple days, the dermatitis comes back. My doctor also told me this would continue for the rest of my life. It's been the same for about 4 years now, and shows no sign of going away. Just another thing to have to deal with regularly ...