Hose it off every 10 hours before I throw more grease at it.
In the fall I detail clean it and put a coat of wax on it.
I hate washing and waxing stuff, but the 10 hour hose down has saved me amoney a couple times when I spot the beginning of a problem that a light coat of grung was covering.
The wax is required thanks to the crap paint that is put on equipment these days.