Wet sanding urethane

I getting ready to finish-out my 340 Duster and it was painted with Urethane almost a year ago, good paint job but does have a little orage peal. I was told the urethane is a really hard paint to sand if it has cured for a while. I was told to use 2000 grit and rinse the sandin block periodically with water joy soap mix.
Does anyone have advise/experience on how to sand it?