The best product for cleaning sinks Bon AMI or Baking Soda and a mild scrubber pad like ScotchBrite.
Bar Keepers Friend is also amazing but is a bit more harsh for the environment.
These products should only be used on stainless sinks.DO NOT use on stainless appliances or it
will scratch them (although baking soda is okay to use on appliances with a soft sponge).