How to get rid of classic neck choke.
Why push attacker's both hands together and not one hand as people instinctively would have done? That's because pushing on one hand would cause his hand to fold the normal way, which he can resist.
When pushing both the hands together you are basically pushing to fold his hand the wrong way. Which unless he gives up, will break his hand.
If you notice closely that's the common technique in all martial art strikes. Try to fold the opponents hand at his elbow the wrong way. He will fall or give up.