Just last year the Pope asked all Catholics to pray the rosary for the conversion of Islam. Isn't that what you would pray for too? I have not heard any idea from any Catholic or nonCatholic that strikes me as more intelligent,more holy or more likely to be effective than prayer,have you?
"...and pray on my behalf, that utterance may be given to me in the opening of my mouth, to make known with boldness the mystery of the gospel,..." Ephesians 6:19
We don't need to pray for people conversions. We should be praying that we may be faithful in opening our mouths to share the gospel.