Ok, here's my best answer after two sessions this afternoon, considering what you are asking.
It hurts, like hell. Then it is relieving, and then it puts you into a trance (sub space, as they call it). First, you feel like your skin is on fire, then you are angry, then you are peaceful, then you are angry again, and then appreciative. i really don't know what you are asking.... it hurts. i mean, you've felt pain before right? but imagine pain that you appreciate and need, and then it all changes, and again, and then again.