Genners:

Please ***do not*** use shaving cream (or other cleansers) on headstones!
Even if the immediate result is a wonderfully contrasted carving, there
can be major long-term effects. The acids in the shaving cream can
erode the headstone. And even if there are no acids mentioned in the
ingredients, "the reactions of the non-acidic chemicals in the shaving
cream turn slightly acidic once the cream is applied.

Read more about it here

http://www.memorials.com/Headstones-Cleaning-and-Preservations-of-Tombstones-information.php
[or http://tinyurl.com/m56bawx --Mod.]

Rubbing, chalking, using powder or flour are also *not* recommended.

Here are some safer ways to obtain a clearer inscription:

Water, mirrors, snow, and aluminum foil (taped only on the foil, with no
tape touching the stone)

http://saveagrave.net/hard-to-read-stones

Barbara Zimmer
Norfolk Virginia