A lawn mower deck cleaning system and method is provided for cleaning mower decks and other interior surfaces that become layered with debris over time. The cleaning system comprises an elongated conduit affixed to the mower deck that provides a means of communicating a solid material from a hopper directly into the mower deck interior. The upper end of the conduit comprises a hopper with upstanding sidewalls and an interior configured to support solid ice material therein. The lower end of the conduit terminates at a junction along the mower deck surface, whereby solid ice moves through the conduit, through the junction and into the mower deck interior to be jettisoned against the walls of the mower deck and ultimately pulverized by the spinning mower blade. The cleaning system is one contemplated for lawn mowers and other reciprocating machinery, as well as both push mowers and ride-on mower decks.