Plain old white vinegar and a little baking soda is all you need to keep the sink clean and shiny.
White vinegar is one of those things that does a little bit of everything. It is acidic so it kills mold spores, bacteria and germs, it cuts grease and it's both safe for the environment and really inexpensive.
Mix a couple of cups of white vinegar and a couple of cups of hot water.
Use a microfiber cloth to scrub away grease and grime and then rinse the whole sink with more hot water and wipe it dry with a second microfiber cloth.
This will absorb any excess water and leave you with a streak free shine.
In between cleaning, a little bit of plain baking soda on a damp cloth with remove fingerprints and smudges.
Don't have any baking soda? Try a chamois. That will also get rid of streaks and fingerprints. That's all there is to cleaning your stainless steel sink. I'm Mrs. Fixit and it's just that simple!