Jesus ate with tax collectors and prostitutes. I don’t think Dr. Graham would object to one of their modern successors hearing the Gospel at his funeral.
And God can raise up wonderful witnesses that can get these dissolute folks thinking seriously about God’s desires for them again, without raising a myriad of red herring issues. I think it’s more about the witnesses believing powerfully in how wonderful God is, than in being all that wonderful in themselves. (All are saved sinners.)