This is not a maids job. This needs to get done by a professional. If you don't want to do it, then don't, but if you "don't want to spend more than a couple of hours" move on and let them hire someone that will take it seriously. It's not a high paying job, but it needs to be done right.
Prosoco makes Dicone 9, a silicone digestant. I would probably just scrape it all off the stone, then pick it off the aluminum, or use a plastic putty knife. MB-9 is a stone safe mold and mildew remover that works really well. Clean up, scrub it down with solvent and let it dry, then re-silicone. Even use a colored silicone to match the stone and make it look good.
It's tedious, but will look very nice when done right.