Hi- I am looking for advice on techniques to clean the underside of my mower deck. I purchased a brand new mower (a first for me) - a 2020 Hustler Raptor SD and I am really enjoying using it. It has slashed my mowing times in half, and I am happy with it's operation and ease of maintenance. One aspect of the upkeep that I am concerned and unsure about is cleaning the underside of the deck. This is a side-discharge mower (I am not using the optional mulching kit that is available from the manufacturer). I am cautious to never cut wet grass, and I am never cut more than a 1/4" off off the grass at a time, in an effort to reduce the possibility of grass sticking / collecting underneath the deck. I clean the underside (briefly) after each use to remove anything that is obvious and large and use a leaf blower on and under the machine to help remove anything that might still be there- but the underside of the deck (and the rubber discharge chute) is now coated with a hard shell of grass "juice" I'll call it. I have tried to scrape it off with a plastic scraper (I also tried using an expired plastic credit card- since I was thinking if a scraper would work- it'd have to be flexible to contour to the shape of the deck). Neither worked. To give you an idea of the tenacity- I can scratch it off using my fingernails in some places, so I know it could come off, but that is not something I'll be doing, as it would be painful, and would take forever.
Is there any harm in leaving it on the metal? I would guess it will promote corrosion, so I am looking for advice on a technique for removing this stuff. Since it's also on the rubber chute (which is flexible) some flaked off when I twisted the chute, so I collected it and took a picture of it (it's the dark colored material angled on top of the white tubing).

I asked the Hustler Dealer that sold it to me, and they told me that they power wash the decks when they do maintenance, but Hustler Customer Service told me NOT to power wash the underside of the deck, unless I also intend on replacing the spindle bearings. I tend to believe the manufacturer, as my previous Craftsman DTY4000 lasted 14 years (I sold it recently, and it's still going as far as I know) and followed these same practices- so I'm keeping the Raptor away from water as much as possible.
Any advice would be very much appreciated.
Is there any harm in leaving it on the metal? I would guess it will promote corrosion, so I am looking for advice on a technique for removing this stuff. Since it's also on the rubber chute (which is flexible) some flaked off when I twisted the chute, so I collected it and took a picture of it (it's the dark colored material angled on top of the white tubing).

I asked the Hustler Dealer that sold it to me, and they told me that they power wash the decks when they do maintenance, but Hustler Customer Service told me NOT to power wash the underside of the deck, unless I also intend on replacing the spindle bearings. I tend to believe the manufacturer, as my previous Craftsman DTY4000 lasted 14 years (I sold it recently, and it's still going as far as I know) and followed these same practices- so I'm keeping the Raptor away from water as much as possible.
Any advice would be very much appreciated.