Thank you all. I prayed the chaplet for him yesterday during the hour of Mercy (3pm).
I’m not sure how much I can personally help him to know the truth. I met him just once about twelve years ago. My wife and he were never close as youths. However, they did have a conversation during the past week for the first time in years. My wife has a particular devotion to the Divine Mercy. I pray she can or perhap already did reveal the Truth to him as you inquired here. If not, I pray they have another opportunity before he passes away (barring a miracle cure).