Try non-homogenized milk--start at 50/50 (raw milk/water) then ween it down to 10% milk. For a quick and effective knockdown, mix Serenade with the mixture (full strength). Many, many studies concluded 50/50 milk was just as effective as many "chemical" fungicides. I would use skim or the "no-fat" variety of milk; half-gallon of skim raw milk is around $5 or so (if your community allows it to be sold).