Griddle tops are similar to cast iron in their use and care. When cleaning either, the most important things to remember are you should use minimal water, never use soap, and always finish with a light layer of oil to protect your seasoning.
The best way to clean a griddle top is to scrape it down with a metal-edge scraper to get all the large debris into the grease cup to be thrown away. (If you want to make clean-up even easier, we recommend using disposable grease cup liners.) If there is anything still stuck to the griddle surface, you can use concentrated shots of water to loosen them up, or even use a scrub pad from a cleaning kit for extra sticky messes.
Finish by spreading a thin, even layer of cooking oil over the surface to prevent your seasoning from drying up and lock out water.