Sorry for my ignorance, but what harmful bacteria predominant to meat will live for that long on a surface? After using my wooden cutting boards for meat, I throughly scrub them and let them dry for at least 48 hours before even putting them away. Salmonella and campylobacter I think are well destroyed by then, and I probably won't even use the board more than once every 5-7 days, always cooking everything cut on it.