I have so far just cleaned Grates, water pan and drip pan in bottom of unit. Just got through washing the grate and use a pot scrubber on them, sponge and dawn in hot water to clean them up. Have not attempted to clean inside of box but when I do I will start with a pan of water and dawn using a sponge that has the scrubber on one side. Shame on me but I have not done any research on how to clean inside.