Does anyone have experience with Grapefruit Seed Extract (GSE)

I have read that GSE can kill AFB, has anyone used this as a preventative for AFB? I donít want to use Tylan or Terramycin if I can avoid it. Many have warned me that if I donít do something to prevent AFB I could lose all my hives quickly. See article text http://www.izs.it/vet_italiana/2004/40_2/39.htm