From a look at the
website, the device lightly compresses the
jugular veins in order to slightly raise blood volume within the skull. If you review resource threads on hanging or the night-night method, you will see that these methods work optimally (and more peacefully) when the
carotid artery is compressed. This cuts off blood flow
to the brain and leads to a relatively quick loss of consciousness, whereas compressing the jugular vein prevents blood from
leaving the skull and results in the very unpleasant 'exploding head' feeling. So even if it were possible to make the pressure on a Q-Collar much greater, it would probably still not target the optimal position. And as something not targeting the right position, it would probably be no more useful than a belt, rope or ratchet.