I don't know about the success part ,but I've used it ,after Talking with Juanse last summer.We did it differently by feeding it in the syrup.We used a 2% solution and had no adverse affects.
We did'nt take the time to get before and after spore counts because of time restraints and getting ready to split,Juanse has facts and figures for his doings.The way I looked at it was it could'nt hurt with hive and bee sanitation at the least ,and wanted to include it in during the late summer operations...for what it's worth.

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