So, Usually I am a melee with Cleave and Great cleave which reset the cool down for Momentum Swing.
I have tried out other cleaves to see if they also reset the cool down of Momentum Swing such as: Exalted Cleave, Avenging Cleave, Eldritch Strike, Strike down, ETC. Something that I have not tried yet, was using the Eldritch burst and Spirit blast from the Warlock enhancement tree. Does anyone know if they reset the cool down of Momentum Swing?