staines on marble

Quoted text begins.many different poultice agents, among them plaster of paris (too messy),
End of quote.

pulp fiber (mixed with de-ionized water to remove alkaline salts from
limestone), and blotter paper or paper towels (when nothing else was
available). My medium of choice is diatomaceous earth, available as swimming
pool filter medium and easily available at supply houses

Regarding a paper poultice, I've made my own (when a commercial variety has
not been available) using sheets of plain white paper and kitty litter
mulched wet in a kitchen blender.

Simon