It's a big chore that everyone neglects: Chipping the dried-on clippings out from under the mower deck. On a large riding mower, this can be a tough, sweaty job. Mower decks must be cleaned or they will lose efficiency, become noisy, and rust out the deck.
The "Cleaning Station" consists of a round metal or plastic plate, about 48" in diameter and 1" thick. Hook a water hose to it, push or drive the mower up on it, and let the mower blade run at reduced speed. Turn on the water, and it will clean itself while you sip a cold one.
Concentric rings can be turned off or on for different size decks from 20" to 52".
An alternative would be plastic pellets the size of moth balls. Move the mower over a shallow pan with a skirt around it. Let the blade turn at reduced RPM, and they will pick up and fling the light pellets against the deck. This should literally blast the clippings off the underside of the deck. It would be a good trick containing the pellets and prevent them from blasting passers by.
I learned that running over pine cones and corn cobs cleans the mower deck really good, but they're hard to find in town.-- bobad, Jun 08 2004 Plus it makes a great kiddy sprinkler toy!-- Knife Knut, Jan 18 2005 random, halfbakery