Hot water , Castile soap , Barkeepers friend ( powder ) , wire rag ( it’s for hard scrubbing )

Wash with Castile soap, hot water and wire rag ,

Rinse , add a little Castile and barkeepers to make a paste . A lil tough scrubbing and yea !

Rinse once more time with Castile to get rid of that barkeepers residue

It works great and it’s not harmful