That will just cause a power struggle. Otherwise they will become like a sponge. They will absorb all the emotion and become very sick physically. They may be in the room but they are looking away, changing the subject, uncomfortable. Often the distractor needs a stronger person to lean on and to structure things.
Reassurance comes in many different forms.
If you are physically present with the person, eye contact and a non-judgmental reflection of what has been said is often enough. This is tricky. Denial is a big concern. We often hear that a family member is in denial, and won't go for testing. Denial is a psychological defense mechanism, an unconscious mechanism that by definition is not privy to the person who is using it.