...using decolorized Iodine on nails is a "Hints from Heloise" - COOL!
Here's a couple of sellers on eBay that have it, so I'd bet a Google search would yield a ton of sources. (Since we sell on eBay for the majority of our 'living', I'll be buying from one of these...to support my fellow sellers).
Here's what one of the sellers writes about it (the links are below)
First aid antiseptic, non-staining. Iodine is an effective, trusted antiseptic; now available without the stain.
Also recommended to strengthen nails (see "Hints from Heloise" below).
This is one of the lowest prices on the internet for this product.
Labeled in English and Spanish.
HINTS FROM HELOISE -- White iodine will rebuild nail strength
A daily application of white iodine on your fingernails for one week will help strengthen them. After the first week, use only once a week. This is not a case of more is better; do not continue to use white iodine on your fingernails every day, or they will become too brittle. It might take several weeks to see any improvement if your nails are paper-thin from using a primer on them (for acrylics) or from being roughed up so the nail products would adhere better.
Since white iodine is relatively inexpensive and easy to use, it's the perfect “help” for soft, damaged fingernails.
Avoid using hydrogen peroxide (or anything containing it) while using white iodine; these two products “don't get along” and can cause your fingernails to turn orange. Also, clean an old fingernail-polish brush with polish remover, and use this to easily apply the iodine to your nails.