Its actually impossible to SWALLOW your own tongue. Danielle does not actually know what the word "swallow" means apparently. Swallow means "To pass through one's esophagus" If these people on youtube swallowed their own tongue according to Danielle, it would pass through their esophagus and this would only be possible if their tongues were disconnected from their bodies. The people on youtube simple fold their tongue backward and it is indeed hidden at the top of their throat. It is impressive, but it is not swallowing. Next time research things before you attempt to tell people to research things and make yourself look cool and smart Danielle.