Anyone done it if so any tips for the resident idiot?
None of those search links go into detail how to clean marble headstones. The one post shows a 6% SH and brush scrub on granite but others have noted marble and strong SH don’t mix.
I’d like to know myself.
I think @Racer posted a .Gov restoration standards link at one time, think it had something on stone
Edit, check this Limestone Restoration on a Stadium - #14 by marinegrunt
Search marble and granite. There is quite a bit of info around of how to clean them