This has been posted here a couple of times before. It comes from the Sep/Oct 2003 newsletter put out by Eric Mussen of the University of California at Davis:
â€œDr. Steve Pernal, who works in one of the last government funded bee research facilities in Beaverlodge, Alberta, Canada, arrived at his job when American foulbrood (AFB) was really causing problems for some commercial beekeepers.
He first looked at possible ways to decontaminate woodenware from hives containing dead larvae, scale, and contaminated food stores.
1. Scorching and Virkon S were about 84% effective.
2. Powered water was 81% effective.
3. Scrubbing was 77% effective.
4. Steam and lye were nearly 100% effective, as is irradiation.â€
Notice there isnâ€™t a huge difference in any of the methods, especially between scorching and using powered water.
Hereâ€™s some of his past newsletters for anyone interested. http://entomology.ucdavis.edu/faculty/mussen/news.cfm