[Quiteria]

I use a handful of baking soda, a few drops of cheap shampoo or dishsoap, and a scrub brush...maybe a small amount of water if the wet tub isn't enough to make a paste as it is. The baking soda kind of absorbs the gunk as you scrub, and the detergent in the shampoo or dishsoap kind of cuts through chemically. Oh, our cheap shampoo is for normal-to-oily hair...if you use something moisturizing or strengthening, I'd stick to dishsoap. It's just that shampoo is handy, and there's usually a bottle with barely any left that no one wants to use because it won't come out without diluting, so I use it for this as part of rinsing it to recycle.