...you know...voodoo, magical powers, spells and witchcraft, cult, "Mary worshipers"?
Maybe it's stuff like this?
From the article:
"Brother Lawrence said he knows there are people who are skeptical about the powers of such holy relics, and the powder's mystery probably will not work on those who do not have faith."
Hat tip: my mom who pointed out the article about the Holy Land by Mary Ann Kuharski (in The Catholic Servant that was in our bulletin) where she mentions that shrine. The rest of her article is lovely but this stuff is just silly..."Take one drink of rock powder per day (husband too) and soon you'll have a baby!". Sheesh.