Necklace through Neck (Magic Polo trick)
In this trick, Dynamo asks for a mint. He puts the mint in his mouth, and then takes his necklace. He then seems to shove his necklace through his neck, and when he pulls it back out, the mint is wrapped around the necklace. Quite a miracle!
Take a look at this mildly disturbing performance:
This trick can be done by putting some glue on your neck. You then simply rub a string over it and the thing basically works on itself. Tilting the head down in the beginning will help to glue the neck skin around the necklace, giving it the creepy look. Then all you have to do is rub the necklace a little bit and pretend like you are cutting your throat.
How does Dynamo get the mint on the necklace? Well, he doesn't actually put it in his mouth in the first place. He slips it onto the necklace when he is getting it ready, concealing it with his hand. When he pretends to pull the necklace out of his neck, he lets the mint slip further down. He makes sure we cannot see this well by moving his hands really fast.
Here is a video demonstration of the technique used to make it look as if the necklace is inside your neck: