We decided to try CleanDeck Graphite coating on the new JD X320. This video follows the process from start to finish. Once it was all done I used the deck wash attatchment and took a peek under the deck. It looked like most of the grass washed right off but there was still a few areas it stuck.
We will try to do an update in a few months to see how the coating holds up.

This also shows the basics of how a x32 deck comes off.