Just want to report on the results after yet some weeks.
The treatment still works. However, a few days ago I had a slight problem with areas of dry skin in the morning. This also implied some scaling of a mild kind in areas that were the most affected with SD earlier. The underlying skin seems fine, though, the redness is gone so it was no big deal.
These problems disappeared after I started applying a thin layer of a good moisturizing cream after the evening oil-wash treatments. I use Ceridal lipogel, a cream without preservatives , perfume, water etc. No other measures were needed, next morning the skin is in extraordinary condition.
Good luck to you all in finding what works for your particular skin type!