use a "magic eraser" mr. clean.
only water needed but add a squirt of dawn dish soap and you should get good results
Cynthia: maybe this will help
I like Barkeepers Friend for the tub.
I like Dollar Tree Awesome Orange in the half gallon, which I pour along the sides or down the walls of the tub, let sit 10 mins and scrub off with a brush. I have gotten the worst tubs clean with this stuff.... I had one client who bathed his 6 twelve foot pythons in it, need I say more.
Lysol Power Scum cleaner in the blue trigger spray bottle with a Magic Eraser or a scrub brush.
Wet & forget shower for a slower, no scrub solution. You can use 2x a week to accelerate the cleaning process then once a week to keep it clean.