Meh. This is right up there with socks that have copper in them. Marketing gimmick.
EM radiation falls off at the square of the distance. By the time another mammal roughly your size is in a position - even with a very sophisticated antenna array and some fancy hardware - to measure anything in the way you reflect, emit, or modify the electromagnetic spectrum/field in a way that would give away your location... you'd be heard breathing and shifting your weight, seen visually, or smelled. Put it this way: if a deer could do it, we'd be using millions of dollars to develop human-flesh-EM-detecting tools for warfighters in the field. There's a reason, instead, that we use thermal imaging, ultrasonic devices, radar/lidar, and other devices/technologies. Put the money towards the costs of getting out in front of more deer and turkeys in better places more often, because that's what puts that tasty meat in the freezer.
Lame...