A Question on Integrate Forces and setting a rigidbody3d position manually

I'm trying to make an action where the player can pick up and throw a rigidbody3d. I want the object to act like a rigidbody when not in the player's hands, but when it is, I want to set the rigidbody position to match a marker3d which is a child of the player.

What's the best approach to something like this? Should I be using integrate forces here? I'm not sure I really understand when and when not to use it.