How do i clean my bathtub?

You could try Scrubbing Bubbles! I have used it cleaning walls and surfaces of dirt and tobacco stains on a house I was working at. I was amazed with the results I use it in my home. Its a spray you apply in the dirty area and let in soak in for a minute or two.. Then wipe away, maybe use some sort of scrub devise with it. Sounds like its a dirty tub...