Prince might be the most prolific proselytizer ever.
If Prince has produces an album where all the tracks are preaching the JW dogma, he could count the time.
Say the album is 45mins long, it's a big hit and goes Platinum. That 45mins times 1,000,000 which is 750,000 hours, not to mention air play on the singles, interviews etc which he could also count. He could have over 1,000,00 hours in field service, without having to knock one door and all to a funky beat.
Together with the contributions he must be giving, because he ain't the most wholesome figure in the celebrity world is he? Why would a fundamentalist Christian cult want a guy in their ranks who wrote such classics as "Darling Nikki"??? - if not for money.
They might put a Prince slant on some Bible stories to sell a few more CDs - how about the story of the flood. "...and it Purple Rained for 40 days and 40 nights.........."