Unclog a kitchen sink

To unclog a kitchen sink because of grease, I like the Roebic Crystal Drain Opener. It is a high concentration base that heats up and dissolves grease and food. 
When applying the drain opener, wear rubber gloves and eye protection. Put 2 tablespoons of the drain opener into the drain and add 2 cups of cold water. You can cover the drain with a plastic bowl to avoid any splattering.
Let set for 20 to 30 minutes then flush with cold water.
If you drain is still slow, add more product and repeat the process.
This product is safer than acids and I like that it can't spill like liquids.
Don't use this in toilets, garbage disposals, aluminum, lead or rusted galvanized pipes.