Witnessing and meditation help in not creating new karma. And meditation, little by little, dissolves karma that has not manifest yet. There are three basic types of karma: The ones that have not manifest yet in the life. The ones we create in this life. And the ones we are born with. As long as we have a body and a mind, we have the third kind. Hard to get ride of these as they really disappear with the falling of the body. It is the first and second types we want to NOT create. This is where meditation and Self-Awareness help.