Thank you Father Heilman for clearing this up. And thanks, too, for your linked article on what is now required for the plenary indulgence for a holy suffering soul.
Roman Catholic Man: I have to admit, I have always struggled with the claim that St. Gertrude received, from our Lord, the promise that, if this prayer is said, 1,000 souls are released from Purgatory. But, if it is true, it is true … or is it? Full article is here.