Doesn't it take like 500 rems of exposure to pretty much do irreversible lethal damage? Either way, I can't see much of a use for one outside of a novelty, seeing as I have a radon detector).
Look at this. Now Rad-X...that's something worth thumbing your joystick over.
Hmm. I GIS'ed "Potassium Iodide" and came up with this as the best picture I could find. Evidently they resemble asprin tablets more than Rad-X. Though, I suppose, if enough people asked for it, they COULD distribute them in red and yellow caplets.