Can Ivory dish soap mixed with water be used to clean marble?

I have been reading on several tombstone conservation sites, and no soaps or detergents should be used. Stone is porous and will absorb like a sponge, and there are ingredients in most soaps/detergents that will cause damage to the stone. Currently a product called D/2 is recommended, and is the cleaning agent used on the White House and various statues and monuments. The most gentle way to clean is to spray it on and allow mother nature to do the rest, since the more you agitate the stone, the more wear you cause on the stone and fine edges of the engraving. If you have a build up of lichen and moss, you can use a toothpick, tongue depressor, or paint stir sticks to remove the bulk of it.