i use stone cleaner to clean our marble shower walls--- the shower is large enough that they don't seem to get 'dirty'/ soap scummy, so it's very easy.

i use same cleaner for our marble floor, but we don't have a marble shower floor, but would probably use the same stuff if we did--although alot more elbow grease i would imagine!

We use a non-acidic cleaner in our marble shower. Floors and walls are marble. You should be able to find something to use at any tile/stone flooring store.