I think it helps more the image of the site owner than the chances of these poor children to be found, (though I don't think it can hurt anything, just don't th

I think it helps more the image of the site owner than the chances of these poor children to be found, (though I don't think it can hurt anything, just don't think it helps much) However hidden GPS tag (in a watch / shoes etc) on my child that only I can use to locate them in the first 3 hours, now that's a solution. Is there anything like this? EDIT: a quick Google search suggests there is, are any of these solutions really work?