Works on the shower doors too.
Takes elbow grease but it works.
LOL!
When my daighter was about 12, she was cleaning the kitchen sink, and said she couldn't get the stain out. Knowing her innate ability to do a job with as little energy wasted as possible, I told her to use some elbow grease. (I was in the living room.)
It was real quiet in the kitchen for a few minutes, and then I hear, "Where is it, Mom?"
"Where is what?"
"The elbow grease. I can't find it under the sink."