micman32...
I have a CC '05 2554 with 60 hours and used the deck wash for the time the other day. To be honest, I was not impressed at all with this feature. When I purchased the unit, the dealer rep told me this feature does not eliminate the need for a good cleaning every so often.
In looking at the underside of the deck, where the hose fitting nozzles are, I found the underside of the nozzles to be caked up themselves...which meant I had to clean those out before any water could spray.
Then, after using the deck wash, it still didn't remove the caked on grass. Essentially, all it did was get the caked on stuff wet which if not removed... will promote rusting. The manual states to run the blades while the system wash is being used. That didn't enhance the effectiveness either.
Perhaps the wash system is more effective if used after each mowing. I don't know the answer to that but as for me...I am of the opinion that a good scraping and an air compressor is the best way to clean the underside of a deck. I will probably not use this feature again.