I have just serviced mine today (Fox Vanilla 2005 RLC forks) for the first time. To be honest, they didn’t need it, internals were clean as a whistle.
THE SECRET WITH FOX FORKS IS:
Wipe the stantions clean after each ride, including the gunk that builds up round the seals.
Keep the stantions lubed, I use a mix of finish line teflon after cleaning, and finish line cross country dribbled on just prior to a ride.
Also store the bike inverted every once in a while, that foam wiper seal can soak up a lot of oil, but the bike needs to be inverted for a few hours fo this to happen.
Other than that I would not fret too much. Having had my forks appart this weekend I am increasingly impressed with Fox stuff.