The Flat Top King gives you a detailed breakdown of how to properly clean your griddle after a meal!

As long as you follow a few simple rules, you'll be able to properly maintain your flat top griddle without much work:
1) Clean as you go - Watch how I use my bench scraper to clean as I'm cooking, so that the flat top never really gets that dirty!
2) Control your temperature - Turn off the burners right before your food is done cooking. There should be plenty of residual heat left to finish carryover cooking.
3) Move food off the heat - While cooking, you can move food off the heat to scrape down that area, and then move it back.