There is a lot of good information on http://docscycling.com/blog/. Thanks "bikenorth"
Also see this: http://www.liquicell.com/assets/pdf/Saddle%20Sores%20(P.%20Kortebein).pdf
I have to agree with "bikenorth": In my case I'm probably struggling with infected hair follicles.
From my original post I forgot to mention at what mileage saddle sores are a problem to me. From reading the posts some people can go bike travel without padded shorts and chamois cream at all. I guess if I "only" do 40 mi/day with frequent rest days I can go without padded shorts and cream. However my pace is approx 125 mi/day with no rest days at all. Padded shorts are mandatory to me in that situation, it would be impossible to have that pace with normal cotton underwear - I think it would be a blood bath.
At the moment there is another interesting thread going on:
I really like primitive camping and I have no need to shower every day. I have never stayed at at motel/hotel/hostel/bed breakfast etc. I very much prefer campgrounds in National Parks, National/state Forests, city parks, fire dept lawns etc. In these situations it is not possible to shower which conflicts with common sense in terms of hygiene as mentioned everywhere: Shower daily, wash your shorts daily. Which makes totally sense. This is why, in the original post, I was interested remedies that could help touring cyclists if showering was not an option.