My wife. It works pretty well for me. She uses some Ka-Boom to help.

We have a travertine surround, which I'm told is like a low grade of marble. After years of fussing with it, I gave up and started using a very dilute solution of bleach and water (1 oz bleach in 32 ounces of water). It's worked the best to date and hasn't caused any noticeable damage to the travertine-- granted this is not something I do all that often. Not sure if I would risk even mild bleach on finer marble though. I'm told that most cleaners will etch these types of stone, and maybe I'll regret this given more time...

When I first agreed to travertine, DH assured me he would squeegie the shower walls after every shower, because that's a good way to keep up on stone-- not surprisingly, that did not last long at all.

Anywho, a few months ago I came across 409 Stone and Steel and decided to try that on a granite counter top we have in a different bathroom. It seems to work well enough and says it is safe for marble and granite-- not to mention it's a lot cheaper than some of the specialty products I've seen at the hardware store. To me, the 409 smells like a diluted version of lime away, though I have no idea if it is even the same ingredients.