Cornmeal anti-fungal?

I just heard on public radio that cornmeal is used successfully as a fungus/mildew suppressor. The person who called with the tip said he sprinkled the cornmeal around the rose bushes and worked it into the ground. Previously he was plagued by black rot on the rose leaves but not since he used the cornmeal treatment.

He also used cornmeal to treat toenail fungus by making a slurry with the cornmeal and hot water, soaking his feet for as long as possible about an hour or so. He didn't say how many times a week he used the soak. Vicks Vaporub is also supposed to be a successful treatment for toenail fungus and a much easier to use remedy. Since I'm on the topic of home remedies, a bar of soap under the bed sheet is purported to relieve leg or toe cramps. My wife plagued by toe cramps tried it and hasn't had a recurrence. Could be the placebo effect but if it works... The soap under the sheet is also supposedly good for restless leg syndrome.

I'll try the cornmeal treatment with our roses, apple trees, dogwoods and magnolias blighted by mildew and let you know how this works along with the spraying of skim milk that girlgonegardening suggested.