to what is thought, participation does not mean one has to answer or even join in a conversation that is acrimonious in it nature. If one of two persons talking to each other starts off on another track and the conversation becomes harsh and blaming and nasty, the best and wisest thing to do is to just keep quiet, that is, if you cannot walk away.
In conversation of a provocative nature, two things happen - first is the reaction to what is said and second is the response to it. (Remember provocation can be inciting or provoking, or it may be something that goes against your grain).
No matter how provocative, no matter how unkind and unfair and harsh the words, your reaction should be to keep quiet. Force yourself to be quiet. For this, twist your fingers, pinch yourself, whatever... Just be quiet. Then decide how you want to respond. You may walk away, but not in anger. But if you want to speak, you'll be surprised to see how calmly you choose what you want to say. You'll see that there is a kind of stillness and peacefulness that pervades your heart and inner self. There is no bitterness inside you, nor hurt, nor anger....just a quietness of spirit. And you feel strong in that quietness.
Try it....it works.