From your iodine page: http://www.earthclinic.com/remedies/iodine.html
Having been trained as a medic in the U. S. Air Force many years ago during the Viet Nam era, I have a working familiarity with Iodine. Back then, the antibiotics we used most for field use were Penicillin and cloromycetin (not sure about the latter's spelling). Cloromycetin was great for surgery in less than sterile conditions but it could have serious drawbacks, frequent or long term use being some of them.
For surface wounds iodine seemed to work for nearly everything since it would absorb "beneath the top skin layers". That was what separated it from other germ killing agents popular back then.
When using Iodine on a wound, it was never placed on the open wound itself, only around the edges of it. Hence its absorption usefulness.