since its a double lapel grab ... i would strike them in the face or throat first (hard) or a short kick / knee to the groing would also be effective as the attacker will be standing directly in front of you the wont be able to block since both his hands are occupied... if some how he doesnt let go ... hmm how do i explain this ... i would lift both my hands up , bring them down with force between both his hand and push them outwards ... its kinda hard to explain this part .. hope you can get the idea... there is also a way of breaking the elbow. but if done correctly i think after the first strike the attacker should be in too much pain to continue to hold you ..... pushing down with your fingers hard at the the bones in at the base of the neck can also be used but it has to be done correctly to be effective. most school teach that ' wristy-locky ' techniques because the wrist is one of the weakest joints and is always exposed when the attacker attempts to punch or grab you.
Would you apply those tactics if they were pulling you forward, perhaps for a nose-nose snarling comp or a headbutt or knee? Or if they were pushing you, would you kick? Or if they were swinging you laterally? As for the wristy-locky stuff. Good to know that that's why it is. I'm releived to know that it isn't because of the effectiveness of the twisty-wristy party tricks....