Thanks for the replies. I wrote a response but it got thrown into the ozone layer somehow so I'll try again.
I have communicated with a researcher who says that it is possible to absorb iron through the skin in small amounts. It seems to work best with certain enhancements like an oil as a carrier and that might also slow oxidation. Since sweat contains chlorides I'm assuming the form is probably going to be ferric chloride. It would tend to turn a purple/dark gray color (like copper turns green from chlorides). I don't expect it's going to be a large source of iron, but for me a little is definitely better than nothing.
I have seen serious cases of acne clear up after adding iron filters to home water supplies so I know iron affects the skin by providing a medium for bacteria to multiply. I don't want to soak my skin or get too much...our municipal water supply has no iron at all so that's not even a daily source of exposure for me.
Since many women are iron deficient, if I see any positive results (which I can easily detect with a hemoglobin meter) it could turn into a viable product for those of us who don't tolerate or absorb oral iron.
I thought a thin woven wire might be best since wrought iron is a bit rough. I have a copper bracelet made that way that is easy to get on and off (kind of like a torque). I saw one iron bracelet online made by a blacksmith that was interesting, but I don't need anything quite that fancy: Iron Bracelet